U.S. Ambassador to the United Nations Nikki Haley on Monday asked the body’s Security Council to impose the strongest possible sanctions against North Korea in response to the rogue nation’s most recent nuclear test, saying “the time for half measures … is over.”

Haley spoke at U.N. headquarters in New York a day after North Korea claimed to have conducted an underground test on a hydrogen bomb.

It was the country’s sixth such test, following five previous ones on a nuclear warhead and recent launches of inter-continental missiles to land such weapons on foreign soil.

The United States is calling for a U.N. vote on sanctions as early as next week.