American Secretary of Defense James Mattis held an informal briefing for the press on Tuesday, in which he addressed concerns about whether or not economic sanctions put into place by the United Nations and the American government were an effective means of dissuading Kim Jong un’s pursuit of nuclear weapons.

There has been a growing debate within the United States, and bolstered by third-party nations like Russia, about whether or not sanctions are an effective method of forcing a shift in North Korean policy.  Kim Jong Un has claimed that no level of interference will be enough to force him to give up on what he seems to believe is the key to a new era in foreign policy for the reclusive state, one where Kim may use the threat of nuclear annihilation as a bargaining chip.

Secretary Mattis made his position on the topic clear, stating in no uncertain terms that sanctions are proving effective, though he also indicated that his criteria for success wasn’t quite as lofty as those who have hoped the financial chokehold would be enough to get the job done alone.

We are putting the leader in North Korea in a position to be aware of — [with] the international community voting unanimously twice now in the United Nations Security Council — … the increasing diplomatic isolation that comes with the economic sanctions,” Mattis said.