US President Donald Trump has raised the prospect of speaking to Taiwan’s President Lai Ching-te, in what would be an unprecedented move for a US leader and a major departure from diplomatic norms.

US and Taiwanese presidents have not spoken directly since 1979, when Washington shifted diplomatic recognition to Beijing from Taipei.

“I’ll speak to him,” Trump told reporters at Joint Base Andrews in Maryland on Wednesday when asked whether he would call Lai before making a decision on whether he will sign off on a major Congress-approved arms sale to the island.

“I speak to everybody. We have that situation very well in hand,” he said before boarding Air Force One, adding, “we’ll work on that Taiwan problem.”

It is not clear whether the Trump administration has moved forward with any plans for a call.