SEOUL, South Korea (AP) - Russia launched a mission Thursday to try to get North Korea back into international disarmament talks, sending its top diplomat to Pyongyang after the North announced it would restart its nuclear program.

Foreign Minister Sergey Lavrov arrived in North Korea for a two-day visit that could include a meeting with leader Kim Jong Il. The North's Korean Central News Agency reported Lavrov's arrival in Pyongyang in a brief dispatch.

North Korea last week expelled all international monitors of its plutonium-producing facilities, vowed to restart them and quit six-nation disarmament talks, after the U.N. Security Council condemned its April 5 rocket launch.

Pyongyang says the rebuke is unfair because the liftoff was a peaceful satellite launch. But the U.S. and others believe it was a test of long-range missile technology.

Lavrov is expected to focus on trying to persuade the North to return to the nuclear negotiating table. South Korean and Russian media reports said he could meet with the North's reclusive leader and deliver a letter from Russian President Dmitry Medvedev.

International Atomic Energy Agency chief Mohamed ElBaradei said earlier this week that the North could restart its nuclear facilities within months — a move that could lead to production of weapons-grade plutonium.

North Korea's relations are not as close with Russia as they were during Soviet times, but the two sides maintain cordial ties. Moscow is a member of the six-party nuclear talks and usually avoids openly criticizing Pyongyang.

In Washington, State Department spokesman Robert Wood said the U.S. is working on trying to get Pyongyang's decision reversed.

Secretary of State Hillary Rodham Clinton told a House hearing that Washington is ready to resume the nuclear talks and that she thinks "strong support that we see among the parties against what North Korea's doing will eventually yield fruit," according to Yonhap news agency.

"We have to be strong, patient and consistent and not give in to the kind of back and forth and the unpredictable behavior of the North Korean regime," Clinton was quoted as saying.

Lavrov also plans to visit South Korea on Friday after the North Korean trip.

Tensions on the divided peninsula have been also been running high. The two sides held their first official dialogue Tuesday since Seoul's conservative President Lee Myung-bak took office last year, but the meeting ended without progress.

North Korea rejected the South's request for the release of a Seoul worker being held at a joint industrial zone in Kaesong, just north of the border, for allegedly denouncing Pyongyang's political system. The North also demanded the South pay more to use the factory park.

Relations between the two Koreas have frayed badly as North Korea has denounced the South Korean government's tougher stance. It cut off reconciliation talks and suspended key joint projects, leaving the industrial zone as the only major remaining project.

Under a 2007 six-party deal, North Korea agreed to disable its main nuclear complex in Yongbyon north of Pyongyang in return for 1 million tons of fuel oil and other concessions. In June 2008, North Korea blew up the cooling tower there in a dramatic show of its commitment to denuclearization.

But disablement came to halt a month later as Pyongyang wrangled with Washington over how to verify its past atomic activities. The latest round of talks, in December, failed to push the process forward.