US President Donald Trump and his Chinese counterpart Xi Jinping held a "good" meeting on Thursday in which they agreed that the Strait of Hormuz "must remain open", the White House said.

Iran has largely blocked shipping through the vital waterway, through which a fifth of the world's oil and natural gas normally passes, since the outbreak of war with the United States and Israel on February 28.

"The two sides agreed that the Strait of Hormuz must remain open to support the free flow of energy," the White House said.

China is directly affected by the lack of petroleum crossing the Strait of Hormuz.

More than half of the crude imported by sea to China comes from the Middle East and mainly transits through the strait, according to maritime analytics firm Kpler.

According to the White House, Xi expressed an interest in purchasing more American oil to reduce China's dependence on the strait in the future.

Beijing's own readout of the meeting did not mention any such interest.

For its part, the White House statement did not mention any discussions between the two leaders on Taiwan, the self-ruled island claimed by Beijing and a sensitive subject in US-China diplomacy.

Xi earlier warned that "conflict" between China and the United States could break out, should the issue be mishandled, Chinese state media had reported.