Defense Minister Han Min-koo and U.S. Deputy Secretary of State Tony Blinken held talks Wednesday as the allies are quickening moves to punish North Korea for its defiant nuclear test earlier this month.

"Despite repeated warnings and worries by the international community, North Korea conducted its fourth nuclear test, and it is a grave threat to the Korean Peninsula and the international community," Han said in the opening of the talks held in the Ministry of National Defense in Seoul.

"The South Korean government is discussing international sanctions or bilateral sanctions on North Korea in light of President Park Geun-hye's pledge to make North Korea pay a price proportional (to the test)," the defense minister noted. 

Blinken echoed the view, saying, "There's no greater source of instability than North Korea in Asia."

He said South Korea and the U.S. will face the North Korean challenge "in total solidarity," adding, "There must be a strong response from the international community."

Blinken arrived in Seoul on Tuesday as part of his three-nation trip to Northeast Asia, aimed at a joint counteraction against North Korea.

On Jan. 6, North Korea conducted what it claims was a successful hydrogen bomb test in defiance of United Nations Security Council resolutions that prohibit the communist country from nuclear activities.

Blinken is scheduled to meet with the Park administration's senior officials later in the day, including Foreign Minister Yun Byung-se. (Yonhap)