The United States and South Korea will boost nuclear deterrence planning, the allies’ defense chiefs said Tuesday in Seoul, pledging to hold tabletop exercises focused on the growing North Korean threat next month.

U.S. Defense Secretary Lloyd Austin held talks with his South Korean counterpart, Lee Jong-sup, in a bid to reassure Seoul of Washington’s “ironclad” commitment to defending its ally. The visit came amid rising public support for Seoul developing its own nuclear weapons after North Korea’s record-breaking flurry of missile tests last year – including weapons believed capable of striking the United States.

"Our commitment to the defense of the ROK remains ironclad, and the United States stands firm in its extended deterrence commitment," he said, referring to South Korea by its official name, the Republic of Korea. "That includes the full range of U.S. defense capabilities, including our conventional, nuclear and missile defense capabilities.”

In a joint statement, the two defense chiefs condemned North Korea’s “continued provocations,” including its missile launches and recent drone incursions into South Korean territory, and vowed to “continue to bolster the alliance's capabilities to deter and respond to” North Korea’s nuclear and missile threats, while also enhancing “information sharing, joint planning and execution, and alliance consultation mechanisms.”

The defense chiefs also said that the South Korean Defense Ministry and Pentagon would hold a Deterrence Strategy Committee Table-top Exercise in February, “in order to facilitate alliance discussions on deterrence and response options” in the face of Pyongyang’s saber-rattling.

Austin, writing in an editorial published earlier in the day by the South’s Yonhap news agency, said the exercises would be “increasingly complex scenario-based” and “focused on nuclear threats on the peninsula.”

North Korea has in recent months boasted about its increasingly potent missile and nuclear arsenals, with leader Kim Jong Un ordering “an exponential increase” in the country’s nuclear arsenal, including the “mass-producing” of tactical, or lower-yield, nuclear weapons intended for use on the battlefield.

The growth of Kim’s weapons programs, as well as questions over the U.S. commitment to defending South Korea, have prompted calls for Seoul to consider building its own nuclear weapons or asking the United States to redeploy them to the peninsula.

Earlier this month, South Korean President Yoon Suk-yeol said for the first time that his administration could consider the ideas, though he was quick with a caveat that this was not yet an official policy.

​Opinion surveys in recent years have shown that a majority of South Koreans support the United States redeploying nuclear weapons to the South or the country building an arsenal of its own.

In one example, a new survey by South Korea’s Chey Institute for Advanced Studies found that 7 in 10 South Koreans see the need for Seoul to independently pursue its own nuclear weapons development program as fewer believe the denuclearization of North Korea to be a realistic possibility.

Official U.S. policy ​is to rid the Korean Peninsula of nuclear weapons. Washington fears that if Seoul were to build its own arsenal, it could add fuel to an already burgeoning regional arms race and end all hopes of Kim relinquishing his bombs.

In a move sure to anger Pyongyang, the two defense chiefs additionally pledged to “further expand and bolster the level and scale” of joint military exercises and training, including “a large-scale combined joint fires demonstration this year.”

North Korea considers joint U.S.-South Korea military exercises as a rehearsal for invasion, though Seoul and Washington say they are defensive in nature.

The statement added that the allies would also take steps to make “substantive progress in completing” revisions to their so-called Tailored Deterrence Strategy ahead of another meeting later this year. First devised in 2013, the new strategy will serve as a guideline for future military operations in order to better cope with the North’s increasingly advanced nuclear and missile capabilities.

As for trilateral cooperation with Japan, the U.S. and South Korea committed to following up on developing specific courses of action to facilitate trilateral sharing of missile warning data, which they agreed to discuss at an upcoming meeting of the three countries’ defense chiefs.