"Secretary Mattis said that the United States remains steadfast in its commitment to the defense of the ROK. He further emphasized that any attack on the United States or its allies will be defeated, and any use of nuclear weapons will be met with a response that is effective and overwhelming," Pentagon spokesman Capt. Jeff Davis said in a readout.

The two sides also discussed the current security situation, including the North's missile launch.

Mattis also welcomed a land-swap deal that South Korea's government signed with the Lotte Group conglomerate Tuesday to secure the site for a Terminal High Altitude Area Defense missile defense battery in the country.

"This land transfer will support the alliance's decision to station Terminal High Altitude Area Defense, a defensive weapons system, in the ROK as soon as feasible. This is a critical measure to defend the ROK people and alliance forces against North Korean missile threats," Davis said.

Foal Eagle is a field training exercise involving ground, air and naval forces, which will run through the end of next month.

Separately the allies plan to conduct Key Resolve, a computer-simulated command post exercise, starting March 13.

Han said the exercises contribute to peace on the Korean Peninsula.

The two defense chiefs vowed to monitor the North's possible provocations and strengthen military cooperation to better counter contingencies.

On Feb. 12, Pyongyang test-fired a newly developed intermediate-range ballistic missile in its first provocation since the inauguration of US President Donald Trump. (Yonhap)