WASHINGTON, Feb 16 (AFP) - President Joe Biden on Thursday (Feb 16) said he would talk to his Chinese counterpart Xi Jinping in the wake of the US Air Force shooting down what Washington says was a high-tech Chinese spy balloon earlier this month.

"I expect to be speaking with President Xi and ... we're going to get to the bottom of this," Biden said in his most extensive public remarks since the incident on Feb 4.

While stressing that the United States is "not looking for a new Cold War," Biden said "I make no apologies for taking down that balloon."

"We'll always act to protect the interests of the American people and the security of the American people," Biden said.

The United States has been in a state of alarm since a huge white balloon from China was spotted tracking over a series of top secret nuclear weapons sites, before being shot down just off the east coast.

In the wake of the incident, the US military adjusted radar settings to detect smaller objects and promptly discovered three more unidentified craft that Biden ordered shot down - one over Alaska, another over Canada and the third over Lake Huron off Michigan.

China says the balloon was just a stray weather research craft, but US officials say they have conclusive evidence that the balloon was sent to spy.

The incident has prompted a diplomatic rift, with Secretary of State Antony Blinken abruptly cancelling a rare visit to China. Beijing accused Washington of overreacting and claimed that US balloons had overflown Chinese territory, something the Biden administration denies.

Biden drew a clear distinction between the Chinese balloon and the three smaller objects shot down afterwards.

"We don't yet know exactly what these three objects were," Biden said, while ruling out Chinese involvement - and suggesting they could be civilian craft of some kind.

"Nothing right now suggests they're related to China's spy balloon programme or ... surveillance vehicles from any other countries," Biden said.

"The intelligence community's current assessment is that these three objects are most likely balloons tied to private companies" or research projects, he said.

However, "if any object presents a threat to the safety, security (of) the American people I will take it down", Biden said.

Biden has made a priority of resetting US relations with China, which he describes as Washington's biggest competitor. Despite growing tensions over Chinese ambitions to restore rule over democratic Taiwan, Biden and Xi have said they want to establish "guard rails" to prevent their superpower competition from turning into conflict.

The balloon drama has thrown that project into disarray.

However, Deputy Secretary of State Wendy Sherman said Wednesday that Beijing and Washington have not "stopped communicating and trying to understand each other".

And Biden added that his administration has been "continuing to engage with China" through the tense last two weeks.

"We seek competition, not conflict," he said. "This episode underscores the importance of maintaining open lines of communication between our diplomats and our military professionals."