US President Donald Trump on Friday, January 27 played down talk that he might quickly lift sanctions on Russia, as he stepped onto the global stage alongside Britain's Prime Minister Theresa May, AFP reports.

Britain is a strong supporter of maintaining international pressure on Moscow over its intervention in Ukraine, and Trump took a cautious line at their first joint news conference.

Trump has also come under withering attack at home from hawkish critics in Congress, worried that his stated desire to become friends with President Vladimir Putin might weaken US resolve.

But the new US leader plans to have a telephone conversation with Putin on Saturday, and his aides say he is re-considering the sanctions regime.

"We'll see what happens as far as the sanctions -- very early to be talking about that," Trump said, welcoming May to the White House as the first foreign leader to visit since he was sworn in a week ago.

May took a sterner line, insisting that Putin must live up to the Minsk Agreements that would put an end to Russian military interference in Ukraine.

"We believe the sanctions should continue until we see that Minsk Agreement fully implemented, and we've been continuing to argue that inside the European Union," she said.

White House spokesman Sean Spicer had earlier announced on Twitter that Trump plans to talk to Putin, France's President Francois Hollande and Germany's Chancellor Angela Merkel over the weekend.

France and Germany brokered the Minsk Agreement between Russia and Ukraine and have been pressuring both sides to live up to it.