North Korea on Wednesday accused South Korea of claiming victory for an accord that ended an armed standoff, saying that was "cowardly" and urging the South to be "discreet in words and deeds".

The rival Koreas last week ended a confrontation that brought a rare exchange of artillery fire on one of the world's most heavily fortified borders, striking a deal that opened the possibility for improved relations.

South Korean President Park Geun-hye's approval ratings surged after the deal, which many South Korean media outlets portrayed as a win for her tough stance against the North.

But North Korea's National Defence Commission (NDC) rejected such triumphalism.

"Nothing is more shallow and cowardly than describing the joint statement agreed by North and South together as a victory for one side," the North's state-run KCNA news agency quoted the NDC as saying in a statement.

Under the accord, reached during round-the-clock talks, North Korea expressed regret over the wounding in early August of South Korean soldiers in landmine blasts on their border and the South agreed to halt anti-North Korea broadcasts over border loudspeakers.

South Korea had demanded an apology for the mine explosions in the so-called Demilitarized Zone between them, and some South Korean officials described the North's expression of regret as an apology.

But North Korea denied planting the mines and its NDC said it had expressed sympathy, not an apology.

"Briefly saying 'regret' is nothing more than an expression of 'I feel sorry for what you have been through'," the commission said.

"The landmine explosion in the Demilitarized Zone was merely an accident of the type that happens too often," it said.

Responding to the North Korean statement, the South said both sides should implement the agreement sincerely.

"It is not the time to ride an emotional roller coaster or argue what's right and wrong about the agreement," said Jeong Joon-hee, a spokesman for the South's Unification Ministry, which handles relations with the North.

The agreement opened a channel for dialogue on a range of issues with the aim of improving ties that have been all-but frozen since the sinking of a South Korean naval vessel in 2010.

On Saturday, North Korea agreed to Red Cross talks with South Korea to discuss reunions of families split by the 1950-53 Korean War.