As a partial shutdown of the US government entered its eighth day, with no quick end in sight, the Republican president was in Washington, sending out tweets attacking Democrats and talking up possibly improved relations with China.

The two nations have been in a trade war for much of 2018, shaking world financial markets as the flow of hundreds of billions of dollars worth of goods between the world's two largest economies has been disrupted by tariffs.

Trump and Xi agreed to a ceasefire in the trade war, deciding to hold off on imposing more tariffs for 90 days starting December 1 while they negotiate a deal to end the dispute following months of escalating tensions.

"Just had a long and very good call with President Xi of China," Trump wrote. "Deal is moving along very well. If made, it will be very comprehensive, covering all subjects, areas and points of dispute. Big progress being made!"

Chinese state media also said Xi and Trump spoke on Saturday, and quoted Xi as saying that teams from both countries have been working to implement a consensus reached with Trump.

"I hope that the two teams will meet each other half way, work hard, and strive to reach an agreement that is mutually beneficial and beneficial to the world as soon as possible," Xi said, according to the state-run Xinhua news agency.

Both leaders also extended New Year greetings to people from their respective countries, Xinhua said.

Australian Associated Press