SEOUL, South Korea — The U.S. and North Korea's neighbors might meet soon to find a new way to deal with the communist regime after it snubbed formal talks on ending its nuclear program, conducted an atomic test and threatened war in response to U.N. sanctions, an official said Saturday.

South Korea has proposed the talks with five nations that have been trying to negotiate an end to the North's nuclear program for years. The U.S. and Japan have agreed to participate, while China and Russia have yet to respond, a South Korean Foreign Ministry official told The Associated Press.

He said it remains to be seen where or when the meeting — if it materializes — will take place.

"We have to see how things will play out," said the official, requesting anonymity because he was discussing a plan still in the works.

North Korea and the five countries began negotiating under the so-called "six-party talks" in 2003 with the aim of giving the communist regime economic aid and other concessions in exchange for dismantling its nuclear program. The last round of talks was held in December 2008, when negotiations became deadlocked.

In April this year, the North announced it would no longer participate in the talks. The official said North Korea could be approached for talks, as they are scheduled to attend the Phuket meeting.

Pyongyang has vowed to bolster its nuclear arsenal and threatened war to protest sanctions imposed by the U.N. after its nuclear test on May 25. It also test-fired a ballistic missile and is reportedly preparing for another long-range missile launch and a third nuclear test.

On Saturday, the regime unleashed a fresh round of threats against the sanctions in what has become an almost daily dose of condemnation, transmitted through its official media.

"The implementation of sanctions means war," North Korea's main Rodong Sinmun newspaper said in a commentary carried by the official Korean Central News Agency.

It also warned of a "merciless retaliatory strike" against South Korea if Seoul tries to infringe on the North's sovereignty in the pretext of implementing sanctions.