WASHINGTON/SEOUL • President Donald Trump has said a US trade deal with South Korea has been fully renegotiated and may be signed at the United Nations, where leaders have gathered for the 73rd session of the General Assembly.

In March, the two countries agreed in principle to revise the deal, which Mr Trump had criticised for increasing the US trade deficit with South Korea.

"The trade deal with South Korea has been fully renegotiated and is ready for signature," Mr Trump said at a joint news conference with Polish President Andrzej Duda on Tuesday.

"We may sign it at the United Nations or shortly thereafter. It was a terrible deal for the United States; now it's a fair deal," he said.

South Korea's Trade Ministry is preparing for the possible signing between President Moon Jae-in and Mr Trump during the UN meeting next week, a ministry official said.

She said it was hoped the deal could be implemented on Jan 1 next year, but the schedule depended on parliamentary approval.

Separately, the Trump administration is considering whether to impose tariffs of up to 25 per cent on US imports of vehicles and auto parts from South Korea and other countries under a Section 233 investigation.

Seoul has said it should be exempt from the tariffs, adding that it had already made concessions in autos under the revised trade deal.

South Korean lawmakers have warned that the nation's Parliament will not pass the revised trade deal if the US administration slaps tariffs on Korean cars as part of Mr Trump's threat to protect domestic automakers from global imports.

Mr Chung Eui-sun, executive vice-chairman at Hyundai Motor Group, on Sunday left for the US to meet Commerce Secretary Wilbur Ross and other American officials to discuss tariff exemptions, a presidential aide said.

REUTERS, BLOOMBERG