Top diplomats of the two Koreas have pointedly shunned each other at annual security talks here, dashing hopes of a possible encounter and underscoring frozen inter-Korean relations.

The ASEAN Regional Forum has served as an important venue for discussions on North Korea. This week's forum marked the first time South Korean Foreign Minister Kim Sung-hwan and his North Korean counterpart, Pak Ui-chun, could have held face-to-face meetings on the sidelines since the December death of North Korea's long-time ruler, Kim Jong-il.

Along with top diplomats from Southeast Asian nations and regional powers, Kim and Pak have posed for group photos several times during the forum, but did not even greet each other.

To pay a courtesy call to Cambodian Prime Minister Hun Sen on Thursday, foreign ministers trickled in along an entranceway flanked by scores of cameras. Kim and Pak entered the meeting room separately.

Between each arrival, Kim chatted with other foreign ministers.

Pak simply smiled and shook hands with some ministers, including Chinese Foreign Minister Yang Jiechi. However, Kim and Pak apparently shunned each other and did not even shake hands.

It was a sharp contrast from last year's ASEAN Regional Forum in Indonesia, when the ministers held brief meetings on the sidelines after making diplomatic progress to possibly resume the six-party talks on ending the North's nuclear weapons program.

Diplomatic efforts to resume the six-party talks on ending North Korea's nuclear ambition have been frozen since April, when North Korea defiantly launched a long-range rocket that failed moments after lift-off.

The U.N. Security Council strongly condemned the launch as a disguised test of a long-range ballistic missile and warned the North of further sanctions if it conducts another missile launch or nuclear test.

Concerns persist that North Korea may soon conduct a third nuclear test to make up for its failed launch. The North's previous two rocket launches in 2006 and 2009 were followed by nuclear tests.

Pak didn't respond to a barrage of questions by reporters during the forum.

At one point, a South Korean reporter agitated Pak by shouting out a question about North Korea's new leader Kim Jong-un, "Has Comrade Kim Jong-un married?" In response, Pak only frowned at the reporter.

Little is known about the North's young leader Kim, who is believed to be in his late 20s.

Also on Thursday, North Korea's delegation released an English-language statement at the ASEAN forum, arguing it needs a "nuclear deterrent" to protect itself from what it called "the hostile policy" of the United States.

"The hostile policy of the U.S. against the DPRK (North Korea) is rooted in its intention to eliminate the political ideology and system our people have opted for," the North's delegation said in the statement, renewing calls for a peace treaty with the U.S.

The two Koreas are still technically at war, as the 1950-53 Korean War ended with a cease-fire, not a peace treaty. North Korea, China and the U.S. were signatories to the cease-fire.

"To ensure peace and stability on the Korean Peninsula, the U.S. must give up its hostile policy towards the DPRK and replace the Korean Armistice Agreement with a peace treaty so as to put an end to the state of war between the DPRK and the U.S," the statement read.

In a diplomatic farce, the North's statement cited Paek Nam-sun, a former foreign minister who died in 2007, as its incumbent foreign minister, raising speculation about its motive. (Yonhap News)