UPDATE 2-UN council demands enforcement of N.Korea sanctions

* Council statement strengthens, augments sanctions - U.S.

* U.N. sanctions committee ordered to enforce sanctions

* Chinese envoy urges calm and restraint

(Adds British, U.S., Japanese, Russia, Chinese envoys)

By Louis Charbonneau

UNITED NATIONS, April 13 (Reuters) - The Security Council on Monday unanimously condemned North Korea's long-range rocket launch nearly two weeks ago as contravening a U.N. ban, and demanded enforcement of existing sanctions against Pyongyang.

The U.S.-authored statement, agreed on Saturday by the five permanent council members and Japan, ordered a U.N. sanctions committee to begin activating financial sanctions and an arms and limited trade embargo laid down in a resolution passed two and a half years ago.

"The Security Council condemns the 5 April 2009 launch by the Democratic People's Republic of Korea, which is in contravention of Security Council resolution 1718 of 2006," the statement said.

Some analysts say the passage of the council statement will be largely symbolic and is unlikely to result in a strict enforcement of sanctions against Pyongyang. They say much will depend on China's willingness to enforce the measures.