China's relations are starting to improvewith Japan, India and other countries that former U.S. President Joe Biden courted, just as Donald Trump brings his more unilateralist approach back to the White House.

World leaders congratulated President Donald Trump on his inauguration Monday, with many urging stronger alliances or continued cooperation between their countries and the United States, in carefully crafted social media posts and statements.

Since the election, China has flexed its military might in overt and covert ways, highlighting challenges for the US and its allies.

Chinese President Xi Jinping reaffirmed ties with his Russian counterpart Vladimir Putin on Tuesday, as the two face a more geopolitically assertive US government led by Donald Trump, who criticised the Kremlin's war against Ukraine on the first day of his second term as president.