U.S. Defense Secretary Chuck Hagel on Monday toured the Demilitarized Zone separating the two Koreas as he began his official schedule here to discuss key security arrangements with Seoul and mark the 60th anniversary of their alliance.

“This is a very important location for our relations and probably there is a clear identification of the ROK (Republic of Korea)-U.S. partnership here more than anywhere else,” Hagel told reporters at an observation post in the 4-kilometer-wide buffer zone.

“This is obviously a critical area that assures our joint vigilance for the security and safety of South Korea.”

The two countries on Tuesday celebrate the 60-year-old alliance that has been credited by both sides with deterring North Korean aggression and preserving peace in Northeast Asia.

The Pentagon chief touched down in Seoul on Sunday for a four-day schedule that includes his attendance at the allies’ annual Security Consultative meeting where Seoul’s request to reconsider the timing of wartime operational control is expected to top the agenda.

It is Hagel’s first visit to Seoul as the Pentagon chief since he took office in February.

Hagel along with his South Korean counterpart Kim Kwan-jin walked around the DMZ close to the tense military demarcation line in a show of unity amid signs of Pyongyang reactivating its nuclear facilities.

Satellite images and news reports have recently suggested the North expanded its main nuclear facility in Yongbyon and restarted a graphite-moderated reactor to extract plutonium for nuclear warheads.

“This is probably the only place in the world where we have always a risk of confrontation, where two sides are looking clearly and directly at each other,” he said at the inter-Korean border village of Panmunjeom.

The defense chiefs are to sit for the SCM on Wednesday, where they are to discuss the proposed delay in the OPCON transfer; the creating of their “tailored” deterrence strategy against North Korea’s nuclear arms and other weapons of mass destruction; and enhanced cooperation in the realms of space and cyberspace.

Atop the agenda is the OPCON transfer currently slated for December 2015.

Last May, Kim proposed the allies reconsider the 2015 timetable for the transfer in light of changing security conditions following Pyongyang’s third nuclear test in February and its successful launch last December of a long-range rocket, which experts estimated had a maximum range of 10,000 km.

On his flight to Seoul, Hagel said the time was not right to make any final decision on the issue of a delay in the OPCON transfer, noting that the South Korean military had become “much more sophisticated, much more capable” over the last decade.

Also during the SCM, the allies are expected to finalize their tailored deterrence strategy, which would put forward specific responses to North Korea’s nuclear and other conventional threats, according to Seoul officials.

Earlier in the day, South Korea’s Joint Chiefs of Staff Chairman Gen. Jung Seung-jo and his U.S. counterpart Martin Dempsey held their Military Committee Meeting in Seoul where they furthered consultations over the OPCON transfer and the allies’ future commanding structure.

The two militaries have reached agreement that the allies would virtually retain the key roles of the Combined Forces Command ― a decision that ditches an earlier agreement to dissolve the CFC upon the OPCON transfer and build a military coordination body.

Meanwhile, the USS George Washington, a 97,000-ton aircraft carrier belonging to the U.S. Seventh Fleet, is reported to be deployed to Busan around this weekend to join the allies’ regular naval exercise to take place in the East Sea next week.

During his stay here before departing for Japan, Hagel is also to preside over a change-of-command ceremony at the U.S. Forces Korea headquarters in Seoul next Wednesday. Gen. Curtis Scaparrotti will replace Gen. James D. Thurman.

By Song Sang-ho (sshluck@heraldcorp.com)