The United States is to postpone a visit by secretary of state Antony Blinken to Beijing following the discovery of what is suspected to be a Chinese surveillance balloon hovering above the state of Montana.
The Biden administration had come under pressure from Republicans in Congress to take action following revelations about the balloon on Thursday.
US media reported on Friday, citing a state department source, that Mr Blinken had told China’s top foreign policy official Wang Yi that the balloon’s course was a violation of sovereignty and “unacceptable”.
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The Chinese foreign ministry said on Friday that the it was “regretful” that a civilian airship entered US airspace because of forces beyond its control. It said the balloon was conducting climate research and had blown off course.
US officials said on Thursday that the balloon – believed to be the size of two buses – had earlier crossed over the Aleutian Islands in Alaska and Canada and was loitering above Montana.
Montana is the home of a number of sensitive US military installations including intercontinental nuclear missile fields.
Mr Blinken was scheduled to visit China in the coming days – the first such trip by the country’s top diplomat in about six years.
The Pentagon recommended to the Biden administration that the US military should not shoot down the balloon as it could pose a risk to people on the ground.
On Friday the Pentagon insisted that the balloon was a surveillance device and that it was owned by China.
Pentagon spokesman Gen Pat Ryder said the balloon “continues to move eastward and is currently over the centre of the continental United States.” He did not provide a precise location.
He maintained that the balloon did not present “a military or physical threat to people on the ground at this time”.
He also said the balloon had “the ability to manoeuvre”.
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General Ryder said the balloon was about 60,000 feet above the ground, “well above civilian air traffic would normally fly “.
He said the US was “reviewing its options” in relation to dealing with the balloon.
However, he said the military did not recommend shooting it down “out of an abundance of caution” as to the dangers of death or injury the debris would pose to people and property on the ground.
US defence officials suggested the incursion by the balloon did not pose an intelligence risk as Chinese satellites regularly passed over the continental United States.
However, the revelations caused an outcry among Republicans who argued the Chinese balloon was violating US sovereignty. Some criticised the US government for not shooting it down.
Republican congressman Mike Gallagher, the chairman of a new House committee which is to look at the threat posed by China to the US, maintained that the presence of the balloon “makes clear that the Chinese Communist Party’s recent diplomatic overtures do not represent a substantive change in policy”.
Mr Biden did not comment on the balloon or on the scheduled visit of Mr Blinken to Beijing at a press conference on US job numbers on Friday morning.