President Donald Trump described his face-to-face with Chinese leader Xi Jinping on Thursday as a roaring success, saying he would cut tariffs on China, while Beijing had agreed to allow the export of rare earth elements and start buying American soybeans.

The president told reporters aboard Air Force One that the U.S. would lower tariffs implemented earlier this year as punishment on China for its selling of chemicals used to make fentanyl from 20% to 10%. That brings the total combined tariff rate on China down from 57% to 47%

“I guess on the scale from 0 to 10, with ten being the best, I would say the meeting was a 12,” Trump said. “I think it was a 12.”

Despite Trump’s optimism after a 100-minute meeting with Xi in South Korea, there continues to be the potential for major tensions between the world’s two largest economies. Both nations are seeking dominant places in manufacturing, developing emerging technologies such as artificial intelligence, and shaping world affairs like Russia’s war in Ukraine.

Trump’s aggressive use of tariffs since returning to the White House for a second term, combined with China’s retaliatory limits on exports of rare earth elements, gave the meeting newfound urgency. There is a mutual recognition that neither side wants to risk blowing up the world economy in ways that could jeopardize their own country’s fortunes.

When the two were seated at the start of the meeting, Xi read prepared remarks that stressed a willingness to work together despite differences.