North Korea's vow to abandon all peace agreements with Seoul drew a mild response Friday from South Korea's president, who continued to express optimism that the rivals could hold negotiations soon.

President Lee Myung-bak dismissed the North's claim that his government's tougher policies were pushing the divided peninsula toward armed conflict.

"I hope North Korea understands that (South Korea) has affection toward the North, and I think that the two Koreas can hold negotiations before long," Lee said, without elaborating. Still, he was skeptical about sending an envoy to North Korea to help break the deadlock.

Lee's comments came hours after the North vowed to abandon a nonaggression pact and all other peace agreements with South Korea. The communist country also said it would not respect a disputed sea border with the South.

Some analysts characterized the rhetoric as just the latest in a nearly yearlong campaign to pressure Seoul's conservative, pro-U.S. president — and also attract the attention of President Barack Obama's new administration.

Others saw signs the North is gearing up for armed provocation, possibly a naval skirmish over the Koreas' disputed Yellow Sea boundary — the scene of deadly battles between the two navies in 1999 and 2002.

In Washington, State Department spokesman Robert Wood said North Korea's motivation was unclear, but that its "rhetoric is distinctly not helpful."

He said North Korea's threats would not deter the United States from pursuing international talks meant to persuade it to abandon its nuclear weapons.

"Time is of the essence" in the disarmament efforts and the matter is a priority for the new administration, Wood told reporters.

Lee described the North's remarks as "not unusual" and indicated Seoul will wait until North Korea is ready for talks in good faith.

"South-North relations should be at a starting point where they can trust, respect and talk to each other," Lee said in a televised round-table meeting.

However, Kim Yong-hyun, a North Korea expert at Seoul's Dongguk University, said the North's comments could presage military moves.

"This signals that North Korea will stage a provocation" — probably near the maritime border, Kim said.

Any skirmish would probably be limited in scale and intensity because North Korea is aware that serious clashes would irreparably harm relations with Seoul — and with Obama's administration, he said.

South Korea's Defense Ministry said its troops remain on alert along its land and sea borders, although there were no unusual moves by the North's military.

The two Koreas technically remain at war because their three-year conflict ended in 1953 with a truce, not a peace treaty. The peninsula remains divided by a heavily fortified border, with thousands of troops stationed on both sides.

Relations had warmed considerably over the past decade, with previous liberal governments in Seoul adopting a "sunshine policy" in which aid was extended to the impoverished North as a way to facilitate reconciliation.

But Lee has not pledged to observe accords signed by his predecessors — a stance North Korea says proves his hostility. The North cut off reconciliation talks soon after he took office nearly a year ago.

On Friday, the North's Committee for the Peaceful Reunification of Korea — a ruling communist party organ in charge of ties with Seoul — declared all past peacekeeping accords with the South "dead," claiming Lee was escalating tensions.

"The group of traitors has already reduced all the agreements reached between the North and the South in the past to dead documents," the committee said in a statement carried by the state-run Korean Central News Agency.

Both Koreas are watching to see how Obama's North Korea policy takes shape.

After eight years of icy relations with the Bush administration, North Korea hopes to have improved ties with Obama, analysts say. Obama has said he would be willing to meet with North Korean leader Kim Jong Il if it advances the effort to disarm the North of its nuclear capabilities.

North Korea, which tested a nuclear device in 2006, signed a pact in 2007 with five other nations — the U.S., South Korea, Japan, Russia and China — in which it agreed to dismantle its nuclear program in exchange for aid.

That process has been stalled since August, and talks in Beijing in December failed to get the process back on track.