Though Beijing has confirmed the first was from China, US officials are yet to give further details about the nature of the three latter objects, which so far remain unidentified.
Here, Sky News takes a look at when and where the four objects were shot down, and what we know so far.
4 February
The first object, described by US officials as a suspected Chinese “spy” balloon, was first spotted by US air defence systems flying towards Alaska from the Bering Sea.
Image: A high-altitude balloon over Billings in Montana
The balloon moved through Canada before dipping back into the US and out off the coast of South Carolina, where it was shot down with a missile fired by an F-22 fighter aircraft, about six nautical miles off the coast near Myrtle Beach.
Advertisement
A US defence official said the aircraft was a spy balloon and that China had intended to use it on sensitive military sites.
However, China insisted the balloon was used for meteorological and other scientific research and had been blown off course.
In a statement, the Chinese Foreign Ministry called the shooting down of the balloon an “obvious overreaction” that “seriously violated international conventions”.
10 February
A second object, described as being “about the size of a small car” was spotted by the North American Aerospace Defense Command (NORAD) near Alaska and downed on 10 February.
According to Pentagon press secretary Brigadier General Patrick Ryder, the object, which was hovering at an altitude of around 40,000ft, was “not similar in size or shape” to the balloon shot down off South Carolina.
Please use Chrome browser for a more accessible video player
1:03
Unknown object shot down by US was ‘size of small car’
Two US F-22 warplanes were dispatched from Joint Base Elmendorf-Richardson near Anchorage, Alaska, and the object was shot down over sea ice near Deadhorse.
US officials said a search team had been sent to recover debris from the object in order to identify what it is and where it had come from.
11 February
A third object, again unidentified but described by US officials as “much smaller” than the suspected spy balloon, was tracked entering US airspace over Alaska before drifting over Canada.
Canadian officials described the object, which was flying at an altitude of around 40,000ft, as “small” and “cylindrical” and that it “posed a reasonable threat”.
Again, US F-22 jets tracked the object, while Canadian CF-18 fighters and CP-140 maritime patrol craft also joined the operation.
The object was shot down by a US F-22 over a central area of Canada’s Yukon Territory, on the orders of Canadian Prime Minister Justin Trudeau.
Please use Chrome browser for a more accessible video player
0:36
The object was shot down by a US F-22 fighter jet.
“To our knowledge, this is the first instance of Norad downing an object in Canadian airspace, and the importance of this moment should not be underestimated,” said Canada’s Defence Minister Anita Anand.
12 February
On Sunday, US officials confirmed another unidentified object had been shot down by fighter jets over Lake Huron on the US-Canada border near Michigan.
This time the object was flying at a considerably lower altitude, around 20,000ft.
It was shot down by an F-16 jet, on the orders of Mr Biden, due to concerns that its altitude and flight path could endanger civilian planes.
A senior US official, speaking anonymously, described the latest object as having “an octagonal structure with strings hanging off but no discernible payload”.
In a statement, the Pentagon said: “Based on its flight path and data we can reasonably connect this object to the radar signal picked up over Montana, which flew in proximity to sensitive DOD [Department of Defense] sites.
“We did not assess it to be a kinetic military threat to anything on the ground, but assess it was a safety flight hazard and a threat due to its potential surveillance capabilities.”
US Air Force general Glen VanHerck admitted he did not know what the last three objects shot down were or how they stayed aloft.
However, he told reporters they were not the same as the Chinese “spy” balloon.
“We’re calling them objects, not balloons, for a reason,” he said – also refusing to rule out any explanation when asked if they could be extra-terrestrial.
Rudy Giuliani has been hospitalised following a car crash in New Hampshire, a spokesperson for the former New York City mayor said.
Mr Giuliani suffered “a fractured thoracic vertebrae, multiple lacerations and contusions, as well as injuries to his left arm and lower leg” when his vehicle was struck from behind while driving on a highway near Manchester on Saturday evening, according to Michael Ragusa, Mr Giuliani’s head of security.
“He sustained injuries but is in good spirits and recovering tremendously,” Mr Ragusa said in a statement on X, adding: “This was not a targeted attack.”
Mr Giuliani was in a rental car and “no one knew it was him”, according to Mr Ragusa.
His head of security said the 81-year-old had been “flagged down by a woman who was the victim of a domestic violence incident” and contacted police on her behalf. The crash shortly after was “random and unrelated” to the domestic violence incident, Mr Ragusa said.
Image: Rudy Giuliani attended Donald Trump’s inauguration ceremony in January. Pic: Julia Demaree Nikhinson/Pool via Reuters
Mr Giuliani, who worked as an attorney for Donald Trump in his failed efforts to overturn the results of the 2020 election, is expected to be released from hospital in a few days.
His son, Andrew Giuliani, thanked people for reaching out after hearing about his father’s accident, writing on X: “Your prayers mean the world.”
More on Rudy Giuliani
Related Topics:
“As a son, I can tell you that I’m honored to have a Dad that I can call the toughest SOB I’ve ever seen,” he added.
This breaking news story is being updated and more details will be published shortly.
Palestinian President Mahmoud Abbas and 80 other officials have been blocked from attending September’s annual meeting of the United Nations General Assembly in New York.
US secretary of state Marco Rubio has revoked the US visas of delegates from the Palestinian Authority (PA) and Palestine Liberation Organisation (PLO), and denied others from applying for one.
It is the latest step by Donald Trump’s administration to target Palestinians with visa restrictions, and follows the suspension of a programme to allow injured children from Gaza to receive treatment in the US.
Image: Mahmoud Abbas addressed the general assembly in 2024, but is barred from next month’s meeting. Pic: Reuters
“It is in our national security interests to hold the PLO and PA accountable for not complying with their commitments, and for undermining the prospects for peace,” a statement from the US State Department said.
It added that, to be considered partners for peace, both groups “must consistently repudiate terrorism, and end incitement to terrorism in education, as required by US law and as promised by the PLO”.
Israel declared Gaza’s largest city a dangerous combat zone on Friday.
The army launched a planned offensive that has drawn international condemnation.
Please use Chrome browser for a more accessible video player
0:44
Thick smoke rises from Gaza City after Israeli strikes
Foreign ministers from Iceland, Ireland, Luxembourg, Norway, Slovenia and Spain released a joint statement saying the military operations in Gaza City will cause “intolerable deaths of innocent Palestinian civilians”.
Hundreds of thousands of Palestinians are sheltering in Gaza City while enduring famine.
Image: An Israeli armoured vehicle in northern Gaza on Friday. Pic: AP
Image: Palestinians ride a truck carrying humanitarian aid in Gaza City. Pic: AP
The Palestinian ambassador to the United Nations (UN), Riyad Mansour, said Mr Abbas had planned to lead the delegation to the UN meetings and was expected to address the general assembly at the general debate, which begins on 23 September.
He was also expected to attend a high-level meeting co-chaired by France and Saudi Arabia on 22 September about a two-state solution, a broad idea involving Israel coexisting with an independent Palestinian state.
The State of Palestine is an observer member of the UN, meaning it can speak at meetings but not vote on resolutions.
Image: The State of Palestine cannot vote on UN resolutions. Pic: AP
US decision ‘contravenes international law’
The Palestinian Authority “expressed its deep regret and astonishment” at the visa decision, calling it “a violation of US commitments” as the host of the UN, and claiming it “contravenes international law”.
UN spokesman Stephane Dujarric said the world body would be seeking clarification in the “hope that this will be resolved”.
Image: Hundreds of diplomats left when Israeli leader Benjamin Netanyahu began speaking at the general assembly in 2024. Pic: Reuters
The State Department said that the Palestinian Authority’s mission to the UN, comprising officials who are permanently based there, would not be included in the restrictions.
Under a 1947 UN agreement, the US is generally required to allow access for foreign diplomats to the UN in New York.
But Washington has said it can deny visas for security, extremism and foreign policy reasons.
The death toll in Gaza has now risen to 63,025, according to the Hamas-run health ministry, which does not differentiate between civilians and combatants.
It also reported five more malnutrition-related deaths in the last 24 hours, bringing the total number during the war to 322, with 121 of them children.
US President Donald Trump has revoked Secret Service protection for former vice president and 2024 Democratic rival Kamala Harris.
A senior adviser to Harris, Kirsten Allen, confirmed the decision. “The vice president is grateful to the United States Secret Service for their professionalism, dedication, and unwavering commitment to safety,” said the adviser.
Typically, vice presidents receive a six-month security detail from the Secret Service after they leave office, although it had been extended to 18 months for Harris, according to officials.
Initially, then-president Joe Biden extended her security arrangements to one year, or January 2026, according to reports.
However, a Secret Service official told Sky News’ US partner, NBC, that Biden subsequently signed an executive memorandum in January increasing the then vice-president’s protection period even further, to 18 months.
Former US presidents receive Secret Service protection for life.
Harris, who lost the 2024 presidential election to Mr Trump, is due to start a book tour for her memoir, “107 Days”, shortly.
She was the Democratic nominee for 107 days after Biden exited the race in the weeks following a challenging debate against Trump.
Mr Trump has also ended federal security protection for others, including former national security adviser John Bolton. Last week, FBI agents raided Bolton’s Maryland home.
In March, the president ended protection for Joe Biden’s children – Hunter and Ashley Biden.
Harris has not ruled out a possible presidential run in 2028. She announced in July that she would not run for governor of California in 2026.