Trump spoke with Xi on Monday to discuss trade, as well as the talks between Pyongyang and Seoul, according to the statement. Both leaders expressed hope that the negotiations “might prompt a change in North Korea’s destructive behavior,” the White House said. Trump reiterated his stance of exerting “maximum pressure” to compel North Korea to abandon its nuclear program.

The president also “expressed disappointment” that the U.S. trade deficit has continued to grow.

State-run China Central Television said earlier Tuesday that Xi told Trump that the two sides must work together to find solutions to trade and economic disputes. Xi urged both sides to take a “constructive approach” and work “properly” to settle disputes and open up each other’s markets, CCTV said.

After criticizing China during the 2016 presidential campaign, Trump repeatedly praised Xi during his first year in office and the pair have had frequent conversations. Relations have shown signs of strain in recent months, however, as China resists harsher sanctions on North Korea and Trump’s calls for trade concessions.

Xi noted “positive changes” in efforts to get North Korea to resume negotiations over its nuclear weapons program. “Parties concerned should make joint effort to sustain this hard-earned momentum of easing-up,” Xi said, arguing it was necessary to create the conditions to resume negotiations.