President Donald Trump said Wednesday that China has agreed not to send arms to Iran and is “very happy” with U.S. efforts to reopen the Strait of Hormuz.

The claim was made as Washington and Beijing seek to maintain a détente ahead of high-stakes talks between Trump and Chinese President Xi Jinping. The long-contentious relationship between the two countries has been tested further by U.S. accusations that China is covertly aiding Iran militarily and anger in Beijing that its vessels could be swept up in Trump’s push to choke off traffic to Iranian ports amid halting talks over the war.