The United States has vowed to "aggressively" implement sanctions against North Korea while pressing Pyongyang to return to multilateral dialogue.

U.S. State Department spokesman Philip Crowley said during a regular press briefing Friday that due to its latest nuclear test and missile launches, North Korea will face a level of U.N.-approved sanctions previously unseen and that Washington will implement the new sanctions aggressively.

The spokesman hinted at additional financial sanctions on the North, saying the U.S. will continue to look for ways to tighten financial sanctions that affect the leaders of the regime in particular.

However, he said the door is still open to dialogue, adding that he hopes North Korea will at some point come back to the negotiations.