Controversy over Washington’s alleged push to station an advanced U.S. missile defense unit on the peninsula was reignited when U.S. Secretary of State John Kerry raised the issue for the first time during his trip to Seoul.

At a meeting with U.S. troops and Foreign Service officers late Monday, the top diplomat cited North Korea’s ongoing creation of a nuclear arsenal and other “extraordinarily provocative activities” to stress the significance of the deployment of ships, forces and other assets here to prepare for “every eventual outcome.”

“Nobody quite knows what America’s first line of defense in Seoul will do,” Kerry said. 

“This is why we need to deploy ships, forces ... and we are talking about THAAD,” he added, referring to the Terminal High Altitude Area Defense, which is designed to shoot down short-, medium- and intermediate-range ballistic missiles in the final stage of their flight.

South Korea and the U.S. quickly attempted to downplay his remarks, saying that the issue had not been discussed at all between the two governments including at his talks with Foreign Minister Yun Byung-se earlier in the day.

The U.S. Embassy here also reaffirmed this stance.

“The secretary was attending an internal event and speaking to an internal U.S. audience,” it was quoted as saying by Seoul officials.

With Kerry’s comment, however, Seoul’s dilemma is expected to deepen given stiff resistance from China and Russia, which deem a THAAD deployment as de facto participation in the U.S.-led global missile defense program that they say is directed at them.

On Tuesday, Gen. Curtis Scaparrotti, commander of the U.S. Forces Korea, also said that the allies were “each considering” the matter and will engage in formal discussions “eventually.”

“At some point in the future I think we will consider it (deployment) when the time is right. … Both the countries share consideration not only of military factors but also political factors,” he was quoted as saying by the Munhwa Ilbo after a forum in Seoul. 

During his speech, he also introduced plans to adopt new military assets and integrate the existing ones as part of efforts to modernize the alliance and beef up its defense capabilities, citing Pyongyang’s growing threats in the wake of its recent submarine-launched ballistic missile ejection test and past intercontinental ballistic missile launches.

Scaparrotti has been the main driving force behind the debate since he said last June that THAAD would help head off mounting North Korean threats by providing a “greater sensor array, better awareness of the threats and add to the interoperability of all of our systems.”

In March, the USFK confirmed that it had conducted site surveys of places around the country where THAAD might be stationed.

The furor had slightly subsided following U.S. Secretary of Defense Ash Carter’s joint news conference last month with South Korean Defense Minister Han Min-koo where he said the two countries have yet to begin any discussions and that THAAD batteries were still in production.

Seoul has since maintained its so-called “three noes” line: “no consultations between the allies, no request from the U.S., and no decision made.”

The upbeat assessment and related remarks of top Washington officials is likely to speed up internal discussions ― and controversy ― in both countries and prompt official talks, observers say.

Rep. Yoo Seung-min, floor leader of the ruling Saenuri Party and a member of the parliamentary defense committee, said the THAAD issue should be on the agenda for a summit between President Park Geun-hye and U.S. President Barack Obama in Washington next month.

“North Korea’s ground-based missiles already pose existential military threats and now with the SLBM becoming an additional threat, the alliance can effectively counter them only if they establish an optimal missile defense scheme as soon as possible,” he told a party meeting Tuesday.

“It is abnormal for an ally to repeat the ‘three noes’ at a time when key officials from the State and Defense Departments as well as the USFK have floated THAAD and missile defense.”

By Shin Hyon-hee (heeshin@heraldcorp.com)