UNITED NATIONS, July 13 (Reuters) - North Korea's launch of an intercontinental ballistic missile (ICBM) was an exercise of its right to self-defense "to deter dangerous military moves of hostile forces and safeguard the security of our state," the country's U.N. envoy told the Security Council on Thursday during a rare appearance.

The 15-member Security Council met after North Korea said it tested on Wednesday its latest Hwasong-18 ICBM, adding the weapon is the core of its nuclear strike force.

"We categorically reject and condemn the convening of the Security Council briefing by the United States and its followers," North Korea's U.N. Ambassador Kim Song told the council.

North Korea last spoke at a council meeting on its nuclear and ballistic missile programs in December 2017, diplomats said.

North Korea - formally known as the Democratic People's Republic of Korea (DPRK) - has been under U.N. sanctions for its missile and nuclear programs since 2006. This includes a ban on the development of ballistic missiles.

For the past several years the council has been divided over how to deal with Pyongyang. Russia and China, veto powers along with the United States, Britain and France, have said more sanctions will not help and want such measures to be eased.

China and Russia blame joint military drills by the United States and South Korea for provoking Pyongyang, while Washington accuses Beijing and Moscow of emboldening North Korea by shielding it from more sanctions.

"Russia and China have prevented this council from speaking with one voice. And with these repeated launches, Pyongyang is demonstrating it feels emboldened," Deputy U.S. Ambassador to the United Nations, Jeffrey DeLaurentis, told the council.