President Yoon Suk Yeol on Tuesday asked the US defense chief to arrange bilateral consultations to establish “effective” extended deterrence mechanisms which could dispel South Koreans’ concerns over North Korean nuclear threats.

In return, US Defense Secretary Lloyd Austin pledged to make every effort for combined defense to clear up South Korea’s doubts over the credibility of the US security commitment and nuclear assurances, senior presidential secretary for press affairs Kim Eun-hye said in a written statement.

“Secretary Austin committed to making efforts to gain the trust of the South Korean people by further strengthening US extended deterrence against North Korea nuclear and missile threats,” Austin was quoted by Kim as saying.

The remarks came amid growing debate on South Korea’s nuclear policy in the face of North Korea’s explicit threats of tactical battlefield nuclear weapons. North Korean leader Kim Jong-un urged the country to mass-produce tactical nuclear weapons capable of striking targets within South Korean territory, labeling South Korea as an “undoubted enemy” at the North’s latest year-end party plenum.

Seven out of 10 South Koreans see the necessity for South Korea to independently develop nuclear weapons, according to a poll of 1,000 adults jointly conducted by Seoul-based Chey Institute for Advanced Studies and Gallup Korea released on Monday.

At the meeting in Seoul, Yoon also stressed the need to stage “realistic training exercises” in preparation for changing security situation on the Korean Peninsula, Kim said.

Seoul and Washington have agreed to expand the scale of combined field training exercises this year and springtime combined field training exercises, dubbed Freedom Shield, for 11 days without any breaks. The drills will be the longest to be held to date.