South Korean First Vice Foreign Minister Cho Hyun-dong, left, clasps hands with his U.S. and Japanese counterparts, Wendy Sherman, right, and Takeo Mori, respectively, at the outset of a trilateral consultation meeting in Tokyo, Oct. 26. Yonhap

A senior U.S. government official said Wednesday Washington will support the self-defense capabilities of Taiwan in cooperation with South Korea and Japan.

Deputy Secretary of State Wendy Sherman was speaking to reporters just after trilateral consultations in Tokyo with her counterparts from the Northeast Asian allies.

"We will support Taiwan's ability to defend itself and our stance regarding Taiwan remains as it has been for many years now," Sherman said at a joint press conference with Cho Hyun-dong of South Korea and Takeo Mori of Japan.

She added that the three sides discussed the issue and that they "all agreed that there needs to be peace in the Taiwan Strait."

"It is critical for the commerce of the world. It is critical for peace and security," Sherman said.

The trio urged North Korea to refrain from further provocations and warned of an "unparalleled" scale of response in case it pushes ahead with another nuclear test.

"The three countries agreed to continue close cooperation amid North Korea's adoption of an aggressive nuclear policy and the increased threat of using nuclear weapons," Seoul's vice foreign minister said.

South Korea will also strengthen its deterrence against North Korea through the combined defense posture with the U.S. and tripartite security partnerships involving Tokyo, Cho said.

This week's session came amid rampant speculation that the Kim Jong-un regime may soon carry out another nuclear test and carry out additional provocative acts.

Officials in Seoul say the secretive North is apparently all set for its first nuclear test since September 2017.

On Tuesday, Cho had one-on-one consultations with Sherman with a focus on Washington's commitment to extended deterrence for Seoul.

In a separate bilateral meeting with Mori on the same day, Cho discussed the protracted row over wartime forced labor and other areas of mutual concern and agreed to consult each "with a sense of tension and speed." (Yonhap)