President Obama just hours ago warned that North Korea's latest nuclear test and further provocative actions would be met with "serious consequences."

The White House was reacting to a 5.0 magnitude earthquake in North Korea that was the likely result of that country's fifth nuclear test in the last few years. Various reports said the blast appeared to be North Korea's largest nuclear detonation yet, and yet was compact enough, indicating the country may have the ability to deliver it on a missile.

White House press secretary Josh Earnest said Obama had been briefed about the incident, and had already reached out to Japan and South Korea.

"The president reiterated the unbreakable U.S. commitment to the security of our allies in Asia and around the world," Earnest said.

"The president indicated he would continue to consult our allies and partners in the days ahead to ensure provocative actions from North Korea are met with serious consequences."

Obama's Defense Department, meanwhile, warned that confirmation of another nuclear test would be a "flagrant violation" of several United Nations Security Council resolutions.

"We will continue to monitor the situation, and Secretary [Ash] Carter will remain in close contact with our South Korean allies as well as others friends and allies in the region," department spokesman Peter Cook said.

The National Security Council released a separate statement said it was "monitoring and continuing to assess the situation in close coordination with our regional partners."