Fumio Kishida and Xi Jinping agreed to try to improve relations between their nations, even as Japan’s prime minister expressed “grave concerns” about China’s military activities in the region.

In their first in-person meeting, a 45-minute encounter late on Thursday in Bangkok, the leaders of Asia’s two largest economies agreed to strengthen communication on security issues. Ties between Tokyo and Beijing have been strained by rising tensions over Taiwan and by their territorial dispute over the Senkaku Islands, known as the Diaoyu in China.

“I expressed my grave concerns about the situation in the East China Sea, including the Senkaku Islands, as well as China’s military activities including the launch of ballistic missiles,” Kishida said after the meeting on the sidelines of the Asia-Pacific Economic Cooperation forum.