U.S. Treasury Secretary Steven Mnuchin said he’s considering a trip to China, adding that he’s “cautiously optimistic” of reaching an agreement that defuses a dispute over trade.

“A trip is under consideration,” Mnuchin told reporters on Saturday in Washington at the IMF’s spring meetings. “I’m not going to make a comment on timing, nor do I have anything confirmed.”

A trip by the U.S. Treasury secretary to China could signal a breakthrough in the spat between the world’s two biggest economies, which have threatened to slap tariffs on each other. A visit would come at a sensitive time for the region’s geopolitics, with negotiations under way on a meeting between President Donald Trump and North Korean leader Kim Jong-Un.

Mnuchin said he met with Yi Gang, governor of the People’s Bank of China, at the IMF gathering this week. The discussions focused on issues related to the Chinese central bank, not trade, said the secretary. Mnuchin said they also discussed China’s planned further opening of some of the country’s markets, a move that U.S. has encouraged and “appreciated.”

Mnuchin said China has been “very helpful” in supporting U.S. sanctions against North Korea, and he welcomed Kim’s suspension of nuclear testing that was announced less than a day earlier.

“We are going to continue the sanctions” and a “maximum pressure” campaign until North Korea abandons its nuclear-weapons program in a verifiable way, he said.

China Talks

Mnuchin indicated he’s involved in a “dialogue” with the Chinese government to resolve the trade dispute. “We’re cautiously optimistic to see if we can try to reach an agreement,” Mnuchin said.

Escalating tensions between the U.S. and China have rattled financial markets and raised concerns the world is barreling toward a trade war. Trump has proposed imposing tariffs on as much as $150 billion on Chinese imports, while China has vowed to retaliate on everything from American soybeans to planes.

Mnuchin also said he met with Russian Finance Minister Anton Siluanov during the IMF meeting, at Russia’s request. Moscow is seeking “clarification” on U.S. sanctions, Mnuchin said, without elaborating. “These are very important tools. We will continue to look at the use of sanctions in all different areas,” he said.

The U.S. has had discussions with Japan on a bilateral trade agreement, the secretary said. Trump had a “very successful” meeting this week in Florida with Japanese Prime Minister Shinzo Abe, Mnuchin said.