UN Secretary-General Ban Ki-moon says North Korea's plan to launch a rocket could be a threat to regional peace.
Ban also says a launch would be a "clear violation" of a 2009 UN Security Council resolution banning North Korea from carrying out ballistic-missile launches.
North Korea’s communist-led regime has announced plans to launch a rocket sometime between April 12 and 16, in order to place a satellite into orbit. Pyongyang insists the goal of the project is scientific reseach.
The United States and its allies have said they are concerned the launch could be a pretext for a long-range missile test.
"I urge the DPRK (North Korea) authorities to refrain from any such acts which will destabilize the situation and peace and stability in the Korean peninsular and which is against the aspiration and wishes of the international community," Ban told reporters during a visit to Malaysia.
Ban said he would discuss the possible launch at a summit with South Korean President Lee Myung-Bak next week and at the March 26-27 international nuclear-security summit in the South Korean capital, Seoul.
The summit will be attended by representatives of some 50 countries. North Korea is not expected to attend. The regime has characterized the summit as an "unsavory burlesque" aimed at justifying a possible nuclear attack on the North by South Korea or its ally, the United States.
On the summit sidelines, the presidents of the United States, Russia, China, Japan, and South Korea are expected to hold talks addressing the North Korean crisis.
The five countries, along with North Korea, comprise the six-country negotiating process whose goal is the North's nuclear disarmament.
North Korea quit the six-country talks in 2009 because of what it described as U.S. hostility and conducted a nuclear test the following month.
Washington has said that a recent bilateral deal between the United States and North Korea has been put in jeopardy by the North's rocket-launch plans.
Under the deal announced earlier this month, the United States would supply 240,000 tons of food aid to the North in exchange for a freeze of Pyongyang's nuclear and missile programs.
With AP and AFP reporting