WASHINGTON: US President Donald Trump on Sunday spoke to Japan's new prime minister, Yoshihide Suga, to congratulate him on taking office and to discuss a "free and open Indo-Pacific" region, which is increasingly dominated by China.

"The two leaders discussed the importance of pursuing our shared vision of a free and open Indo-Pacific, continuing to strengthen the United States-Japan Alliance, and working together to strengthen the global economy," the White House said in a statement.

China is locked in disputes with neighbors including Japan and Vietnam over islands in the South China Sea.