US bars China experts from attending space conference

China has accused the United States of ‘‘weaponising’’ visas after a delegation of Chinese space experts was prevented from attending a global conference in Washington.

Several members of the China National Space Administration, including Wu Yanhua, its vicechairman, were conspicuously absent this week from the International Astronautical Congress, an annual global space conference now in its 70th year.

Mike Pence, the US vicepresident, opened the meeting by declaring America would only seek space co-operation with ‘‘freedomloving nations’’.

A spokeswoman from the Chinese foreign ministry said that the US was ‘‘weaponising visas in defiance of its international responsibilities and obligations’’. She added that the denial of visas to Wu and others undermined Beijing’s ‘‘legitimate and lawful rights’’.

The US has been exerting increasingly tight control over visas to Chinese officials and revoking long-term permits for scholars amid fears of espionage by the Chinese state and corporations. The Trump administration frequently accuses Chinese researchers of stealing US innovations and the Department of Justice is investigating alleged Chinese espionage against US companies and government entities. Intellectual property theft is a key sticking point at the centre of the trade war between Beijing and Washington. The White House has signalled that it anticipates space will become a frontier for tensions.

President Donald Trump has vowed to return Americans to the moon by 2024 while creating a military branch in space. Meanwhile, Beijing’s space programme is advancing rapidly. In January, China became the first nation to land a rover on the far side of the moon.

The State Department rejected Beijing’s accusation that it withheld visas as ‘‘unfounded and baseless’’.

‘‘We cannot discuss individual visa cases since visa records are confidential under US law, but we can confirm that the Chinese delegation is in attendance at the conference,’’ Morgan Ortagus, the State Department spokeswoman, said yesterday.

The US issued 1.3 million visas to Chinese travellers last year, she added.