SEOUL (REUTERS) - US President Donald Trump told South Korea on Saturday (April 8) that he had explained America's position on the deployment of a US-supplied anti-missile defence to China's President Xi Jinping in their summit meeting, according to a statement from South Korea's acting leader.

Trump informed South Korean Prime Minister Hwang Kyo Ahn of his discussions with Xi in a telephone call on Saturday.

China has opposed the deployment of the Terminal High Altitude Area Defence (Thaad) in South Korea which the United States and South Korea say is aimed at countering North Korea's missile threat.

China has increased pressure and imposed restrictions on some South Korean companies doing business in China, which led many in the South to believe Beijing was retaliating against the deployment of the missile system.

"President Trump said he and President Xi held in-depth discussions on the seriousness of North Korea's nuclear problem and how to respond to it, and also said he had conveyed the US position on the Thaad deployment," the statement said.

Trump pressed Xi to do more to curb North Korea's nuclear programme in their summit meeting at Trump's Mar-a-Lago resort in Florida, US Secretary of State Rex Tillerson said.

The US military began deployment of the Thaad system in March, a day after the North test-fired four ballistic missiles.

China has not directly said it is targeting South Korean companies.