BUSAN, South Korea (Reuters) -U.S. President Donald Trump said on Thursday he had agreed to reduce tariffs on China to 47% in exchange for Beijing resuming U.S. soybean purchases, keeping rare earths exports flowing and cracking down on the illicit trade of fentanyl.

His remarks after face-to-face talks with Chinese President Xi Jinping in the South Korean city of Busan, their first since 2019, marked the finale of Trump's whirlwind Asia trip on which he also touted trade breakthroughs with South Korea, Japan and Southeast Asian nations.

"I thought it was an amazing meeting," Trump told reporters aboard Air Force One shortly after he departed Busan, adding that tariffs imposed on Chinese imports would be cut to 47% from 57%.

Trading in global stocks was choppy as Trump revealed details of the deal, with major Asian indexes and European futures swinging between gains and losses. China's Shanghai Composite Index slipped from a 10-year high, while U.S. soybean futures were weaker.

World stock markets from Wall Street to Tokyo had hit record highs leading up to the meeting on hopes of a breakthrough in a trade war between the world's two largest economies that has upended supply chains and rocked global business confidence.

The meeting, which took place on the sidelines of the Asia-Pacific Economic Cooperation (APEC) summit, lasted nearly two hours. Trump shook hands and escorted Xi to his car before the U.S. president was given a red carpet send-off at the airport.

Trump repeatedly talked up the prospect of reaching agreement with Xi since U.S. negotiators on Sunday said they had agreed a framework with China that will avoid 100% U.S. tariffs on Chinese goods and achieve a deferral of China's export curbs on rare earths, a sector it dominates.

But with both countries increasingly willing to play hardball over areas of economic and geopolitical competition, many questions remain about how long any trade detente may last.