Russia urged North Korea on Monday not to go ahead with a plan for its second rocket launch of 2012, saying the launch would violate restrictions imposed by the UN Security Council.
"We urgently appeal to the government of North Korea to reconsider the decision to launch a rocket," the Russian Foreign Ministry said.
Echoing its criticism of the April launch, Russia said North Korea had been warned not to ignore a UN Security Council resolution which "unambiguously prohibits it from launching rockets using ballistic technology."
North Korea is under UN sanctions that ban trading in missile or nuclear technology.
China on Monday also urged all sides not to take any action that worsens the problem.
China believes that maintaining peace and stability on the Korean peninsula and in Northeast Asia accords with the interests of all sides and is the joint responsibility of all sides, Chinese Foreign Ministry spokesman Hong Lei told reporters. He said China will remain in touch and coordinate with the other parties.
But despite growing international calls to cancel the mission, a South Korean government source told Yonhap news agency Monday that North Korea has installed the first stage of a long-range rocket it plans to launch this month.
The source said it was expected that North Korea would need three or four days to erect all three stages required before launching a rocket.
North Korea insists it is a purely "peaceful, scientific" mission aimed at placing a polar-orbiting earth observation satellite in orbit.
In a notification to neighboring countries, Pyongyang said the launch timing would be between 7 am and midday on any day in the given window, Yonhap reported.
According to the notice, the first stage would fall into the Yellow Sea off the Korean peninsula's west coast and the second would come down in the sea some 190 kilometers east of the Philippines.
Meanwhile, reports and officials said Monday Japan has begun deploying a surface-to-air missile defense system and is putting its armed forces on standby ahead of the planned North Korean rocket launch this month.
NHK reported that a naval vessel carrying PAC-3 (Patriot Advanced Capability-3) ballistic missiles left a western Japan naval base on Monday, headed for the country's southern Okinawa island chain. Tokyo is also planning to deploy Aegis warships in neighboring waters, the Yomiuri Shimbun reported.
Officials are preparing to issue an advance order as soon as Friday to shoot down the rocket if it looks set to fall on Japanese territory, after an emergency meeting chaired by Prime Minister Yoshihiko Noda, the Nikkei business daily reported.