North Korea is ready to resume international talks over its nuclear weapons program without “preconditions,” according to a Russian official describing the meeting Wednesday between North Korean leader Kim Jong Il and Russian President Dmitry Medvedev.

Kim also told Medvedev that North Korea is willing to consider a moratorium on nuclear testing and production, said Natalya Timakova, a spokeswoman for the Russian president, who met later with Russian reporters.

Only a week ago, North Korea was threatening to bolster its nuclear production in response to military drills by the United States and South Korea.

North Korea has conducted two nuclear tests, in 2006 and 2009. There were reports last winter that tunnels were being dug to prepare for a third test.

The international talks, which include South Korea, the United States, China, Japan and Russia, broke off in April 2009 when North Korea walked out a month before its second nuclear test. Russia has been eager to get the negotiations going again. A settlement could allow it to pursue overland trade with South Korea, which has long been a Russian ambition.

Toward that end, Medvedev and Kim also agreed Wednesday to establish a commission to work out a deal that would allow Russia to send natural gas to South Korea by way of a pipeline through the North. Pyongyang has been reluctant to play any role that would be helpful to Seoul, but the transit fees the North would receive for the gas could be worth many millions of dollars.

Progress on that project would be difficult without a nuclear deal, and the United States, Japan and South Korea have said that they will return to the talks only if they are assured that North Korea will shut down its nuclear program.

State Department spokeswoman Victoria Nuland said Wednesday that the North’s reported offer to refrain from “nuclear test and missile launches” would, if true, be a “welcome first step, but far from enough.” Pyongyang’s “disclosure last November of uranium enrichment facilities remains a matter of serious concern to us,” she said.

Kim and Medvedev met in the city of Ulan-Ude, which is south of Lake Baikal near Mongolia. Kim arrived, as he has on his two previous trips to Russia, by armored train.

Before his arrival, Russia had announced Friday that it will ship 50,000 metric tons of grain in the next month to North Korea, which is again facing food shortages.

The two leaders also said that they are prepared to resume talks over North Korea’s debt to Moscow, which dates to the Soviet years. (Kim’s train was reportedly given to his father by Joseph Stalin.) That debt was originally denominated in Soviet rubles, and a major complicating factor has been reaching agreement on its current worth. Russia, which assumed the Soviet Union’s debts in 1991, puts the value at $11 billion.

This week South Korean President Lee Myung-bak visited Mongolia, Uzbekistan and Kazakhstan, primarily to discuss energy deals.

Relations between the two Koreas have been especially tense recently. South Korea accused the North of firing artillery at an offshore island this month; the North denied it.

On Monday, North Korea ordered all South Korean workers to leave Mount Kumgang, a jointly run mountain resort in a breathtaking location on North Korea’s eastern coast. The resort and an industrial park near Pyongyang were calculated to bring the two hostile nations closer, by mixing South Korean business expertise with North Korean labor.

The move Monday heightened doubts about the future of the strictly isolated resort. The Seoul government suspended tours from the South after a visiting South Korean was fatally shot there in 2008 while walking along the beach.

Staff writer William Wan in Washington contributed to this report.