This could facilitate a return to six-party talks on nuclear disarmament, which stalled in 2008 when North Korea walked out of them, Reuters says.
A frail-looking Kim, who arrived in Siberia on Tuesday — traveling by armored train because of his fear of flying — met the Russian president at a military base in the town of Sosnovy Bor near Lake Baikal.
Kim told Medvedev, who flew nearly 3,500 miles across Russia to reach Siberia, that he was "having a fun trip."
"Kim Jong-il expressed readiness to return to six-party talks without preconditions," Medvedev's spokeswoman, Natalya Timakova, told Reuters.
"In the course of the talks the North Koreans will be ready to resolve the issue of imposing a moratorium on testing and production of missile and nuclear weaponry," she said.
However, North Korea seems to only want to discuss a moratorium on its nuclear program after talks resume with Russia, China, Japan, South Korea and the United States. Several of the parties involved in the talks would require North Korea to first halt its nuclear testing before any discussion can take place.
U.S. State Department spokeswoman Victoria Nuland told the Associated Press that Kim's reported offer to refrain from nuclear and missile tests was "a welcome first step," but not enough to restart six-party talks.