North Korea may bolster its defenses against the United States and consider restarting "all temporally-suspended activities," state media KCNA reported Thursday, an apparent reference to a self-imposed moratorium on testing its nuclear weapons and long-range missiles.

Tension has been rising over a recent series of North Korean missile tests. A U.S. push for fresh sanctions was followed by heated reaction from Pyongyang, raising the specter of a return to the period of so-called "fire and fury" threats of 2017.

North Korean leader Kim Jong Un convened a meeting of the powerful politburo of the ruling Workers' Party on Wednesday to discuss "important policy issues," including countermeasures over "hostile" U.S. policy, the KCNA news agency said.