The US president has warned the long-standing allies against courting Beijing

US President Donald Trump has warned Canada and the UK that their recent efforts to improve business ties with China are "very dangerous," as both nations seek to reset relations with Beijing amid tensions with Washington.

Trump made the remarks on Thursday at the premiere of a documentary about First Lady Melania Trump. Asked about a recent UK-China summit in Beijing, he said: "Well, it's very dangerous for them to do that." 

The US president went on to say that it's "even more dangerous for Canada to get into business with China."

"Canada is not doing well... You can't look at China as the answer," he said, quipping that China might tell Canada: "you're not allowed to play ice hockey anymore."

UK Prime Minister Keir Starmer told Chinese leader Xi Jinping on Thursday that he wants to build a "more sophisticated relationship" between the two countries, describing ties as having gone from "a golden age to an ice age."

Downing Street said China agreed to halve import tariffs on British whisky to 5% from 10% and confirmed visa-free travel for British nationals visiting for under 30 days. AstraZeneca also set out plans to invest $15 billion in China through 2030 during the trip.

Canada has also sought a thaw with China. Prime Minister Mark Carney traveled to Beijing in mid-January, where he reached a preliminary deal to allow capped imports of Chinese electric vehicles at a 6.1% tariff, while Canada expects China to cut punitive canola tariffs to 15% by March.

At the time, Trump lashed out at Canada, claiming that China is "completely taking over" the country, while suggesting that it "lives because of the United States." He also threatened 100% tariffs if Canada's deal with China goes through.

Both Canada and the UK have been at loggerheads with the US over Trump's renewed push to establish control over Greenland.

Chinese officials said the country's deals with Canada "do not target any third party." As for the UK-China summit, Beijing said the meeting showed a willingness on both sides to strengthen dialogue and expand practical cooperation.