U.S. President Donald Trump said a trade agreement with China might have to wait until after the U.S. presidential election in November 2020, denting hopes of a quick resolution to the dispute which has weighed on the world economy.

"I have no deadline, no. In some ways I think I think it's better to wait until after the election with China," Trump told.

"But they want to make a deal now, and we'll see whether or not the deal's going to be right, it's got to be right."

Investors have been hoping that the United States and China can avert an escalation of their trade tensions which have slowed global economic growth. Washington and Beijing have yet to ink a so-called "phase one" agreement announced in October, which had raised hopes of a de-escalation in their prolonged trade war.

Trump said a deal with China would only happen if he wanted it to, and he thought he was doing very well in the talks.