In Pyongyang's first official comment since test-firing seven missiles on Wednesday, a foreign ministry spokesman said the tests were successful and a "legitimate right of a sovereign state."
North Korea "will have no option but to take stronger physical actions of other forms, should any other country dare take issue with the exercises and put pressure upon it," the statement run on the state-run agency KCNA said.
Earlier this week, North Korea said it would respond to any pre-emptive U.S. military attack with an "annihilating strike and a nuclear war," according to KCNA reports.
U.N. Security Council members have denounced the tests and say they are considering a draft resolution that would impose sanctions on the Communist nation's missile program.
But China and Russia have expressed the desire for a weaker statement -- something that would avoid sanctions and the weight of international law.
"This is the view of the international community, that actions taken should be constructive to maintaining peace in that part of the world," Chinese Ambassador Wang Guangya said.
China is one of five permanent council members, including Russia, with veto power and, as North Korea's neighbor, is Pyongyang's main provider of food, oil and economic aid.
The diplomats and technical experts are to meet again Thursday to go over the language of the resolution behind closed doors.
All of the seven missiles fired by North Korea early Wednesday local time -- six short-range variants of the Soviet-era Scud and one long-range rocket -- fell into the Sea of Japan.
The long-range missile, the Taepodong-2, failed about 40 seconds after it was fired. Some analysts believe it is capable of hitting the western United States.
The White House has said Wednesday's missile launches posed no immediate threat to the United States, but Washington has dispatched Christopher Hill, its top negotiator in the six-party talks, to consult with U.S. allies in Asia.
Six nations -- including the two Koreas, China, Russia, Japan along with the United States -- have been meeting to talk about Pyongyang's nuclear ambitions.
China is sending a top diplomat to Pyongyang next week to try to restart the stalled talks, news agencies have reported. The six-party talks have stalled in recent months as North Korea has insisted on direct talks with Washington.
The United States and Japan had urged Pyongyang to stick with the moratorium on long-range missile tests it declared in 1999, after it fired a Taepodong-1 missile over Japan in 1998.
U.S. President George W. Bush said the missile tests only serve to further isolate North Korea, and vowed to work with the other members in the six-party talks "to remind the leader of North Korea that there is a better way forward for his people."
"It's their choice to make, but what these firings of the rockets have done is isolate the North Koreans further," Bush said.
"And that's sad for the people of North Korea."