WASHINGTON, (Yonhap) -- U.S. President Barack Obama issued a public notice Thursday to extend the national emergency in relation to North Korea that provides a legal and administrative basis for sanctions against the nuclear-armed communist nation.

On the basis of the national emergency declared in 2008 under the National Emergencies Act, the Obama administration slapped tougher sanctions on Pyongyang in April, including a ban on direct and indirect imports of North Korean goods.

"The existence and the risk of proliferation of weapons-usable fissile material on the Korean Peninsula, and the actions and policies of the Government of North Korea that destabilize the Korean Peninsula and imperil U.S. Armed Forces, allies, and trading partners in the region, continue to constitute an unusual and extraordinary threat to the national security, foreign policy, and economy of the United States," Obama said in a statement. "For these reasons, I have determined that it is necessary to continue the national emergency with respect to these threats and maintain in force the measures taken to deal with that national emergency."

The national emergency, first declared on June 26, 2008, by then-President George W. Bush, is due to expire automatically unless the president announces each year that it will continue to be valid beyond the anniversary date of its declaration.