Washington  - The United States warned Monday of "difficult diplomacy" in finding agreement on a strong, effective international reaction to North Korea's defiant launching of a missile over the weekend.

"The issue's a bit complicated, as you know, and it's going to take time," Robert Wood, deputy spokesperson for the US State Department, told reporters. "It's not something, I would suspect, that we could resolve in the next day or so. It's going to take time."

The United Nations Security Council entered its second day of efforts to agree on an answer to North Korea's violation of a 2006 resolution that banned it from conducting ballistic missile activities.

On Sunday morning local North Korea time, Pyongyang launched what it claimed was a satellite. Others said it was a Taepo-dong 2 missile that Japan says crossed its territory.

The US and Japan say that North Korea did not intend to launch a satellite but rather test a long-range missile as part of its nuclear weapons programme. The US says the missile fell into the ocean, while Pyongyang says it put the satellite into orbit.

China and Russia, two of the security council's veto-wielding members, have expressed understanding for Japan's request that the council rule that North Korea violated the resolution.

But the two countries do not agree with the United States, Britain and France, the remaining three veto-wielders, that the rocket launch violated the resolutions.

"It's complex. We've got to make sure that we send a very strong and unified message to the North about this, and to would- be proliferators, those who are out there thinking about either conducting these types of launches or ... to proliferate weapons further," Wood said. (dpa)