The United States is not ruling out the eventual possibility of direct talks with North Korea, Deputy Secretary of State John J. Sullivan said on Tuesday.

“We eventually don’t rule out the possibility of direct talks,” Sullivan said after a briefing with his Japanese counterpart, Vice Minister for Foreign Affairs Shinsuke Sugiyama.

Sullivan will travel to South Korea after Japan. The visit comes ahead of an expected trip to the region by US President Donald Trump next month and as tension in the region grows amid concern over North Korea’s nuclear and missile tests.