U.S. President Donald Trump will speak with Chinese President Xi Jinping and Japanese Prime Minister Shinzo Abe on Sunday, calls that come as frustration builds in the White House over North Korea's nuclear programme.
Trump met with Xi in April, and expressed optimism that the two could work together to curb Pyongyang's atomic ambitions.
'I think he wants to help us with North Korea.'
But in the subsequent weeks the American president appears to feel disappointed.
'I wish we would have a little more help with respect to North Korea from China, but that doesn't seem to be working out.'
The U.S. president initially held off on taking a punitive stance on China over trade, declining to label Beijing a currency manipulator. But last week Washington sanctioned a Chinese bank and shipping company for allegedly facilitating business with North Korea.
Trump is now reported to be considering a tax on U.S. steel imports, which could impact China's steel industry.
Sunday's talks with the leaders of Japan and China come ahead of face-to-face meetings at this week's G20 summit in Germany.