Russian Prime Minister Vladimir Putin on Tuesday urged North Korea to "unconditionally comply with UN Security Council resolutions" on its nuclear development. The previous day, Russian Foreign Minister Sergey Lavrov denounced the North for its shelling of the South Korean island of Yeonpyeong in November.

According to Russia's official international news agency RIA Novosti, Putin and his Mongolian counterpart Sükhbaataryn Batbold issued a joint statement after their talks held in Moscow on Tuesday afternoon. It stressed the need to resume the six-party nuclear talks to discuss the nuclear issue on the Korean Peninsula and urged North Korea "to unconditionally comply" with UNSC resolutions 1718 and 1874.

The resolutions were adopted after the North's first and second nuclear tests in October 2006 and May 2009.

Russian Prime Minister Vladimir Putin (right) talks to his Mongolian counterpart Sükhbaataryn Batbold in Moscow on Tuesday. /Reuters-Newsis

The joint statement urged both Koreas "to solve all issues in political and diplomatic ways through dialogue," while expressing worries about the mounting tensions in inter-Korean relations.

Meanwhile, Russian Army Chief of General Staff Nikolai Makarov in an interview with Interfax on Tuesday said he "ordered the military units in Russian Far East to enhance their combat readiness when the North shelled Yeonpyeong Island" on Nov. 23. "The Russian Army is still watching the region closely and keeps monitoring developments there."