Japan and the United States sent a fresh warning to North Korea Thursday against test-firing a missile, as the allies agreed to step up efforts to stop a launch that would disturb regional peace, the Japanese Foreign Ministry said.

Stephen W. Bosworth, the new U.S. envoy on the North, and his Japanese counterpart, Akitaka Saiki, agreed "to urge North Korea not to take an action that would harm the region's peace and stability," the ministry said in a statement.

The two envoys said a launch — even that of a satellite as Pyongyang claims — would violate U.N. Security Council resolutions, and agreed to cooperate, along with Seoul, to achieve denuclearization of the Korean peninsula, the ministry said.

Bosworth is in Tokyo as part of his Asia tour to discuss resuming stalled disarmament talks.

Saiki and Bosworth refused to comment after their talks, their first since the U.S. envoy was appointed.

The North says it plans to send a communications satellite into orbit as part of its space program. Its neighbors, however, believe it intends to test-fire a long-range missile, a launch that uses a similar delivery system as a satellite.

Bosworth, who was in Beijing early Thursday, said that China and the U.S. were united in opposition to Pyongyang's alleged move.

Japanese officials have said Tokyo may seek additional sanctions against North Korea in case of a launch. Defense Minister Yasukazu Hamada indicated that it could use a missile shield to shoot one down.

North Korea is banned from engaging in any ballistic activity under a U.N. resolution passed in 2006 after the regime conducted a nuclear test and unsuccessfully test-fired a missile.

Bosworth is scheduled to meet with Prime Minister Taro Aso and Foreign Minister Hirofumi Nakasone on Friday before heading to Seoul on Saturday.