U.S. Ambassador to the United Nations Nikki Haley warned North Korea on Friday that she is more than willing to let Defense Secretary Jim Mattis deal with the nuclear threat from Pyongyang if sanctions do not work.

Haley said recent sanctions have “strangled” North Korea’s “economic situation,” calling the impact “dramatic.” 

But she said there’s only so much the U.N. Security Council can do “when you cut 90 percent of the trade and 30 percent of the oil.”

“So having said that, I have no problem kicking it to General Mattis because I think he has plenty of options,” Haley said at the White House briefing, where she and National Security Adviser H.R. McMaster previewed U.S. efforts at the U.N. General Assembly next week.