North Korean leader Kim Jong Un ordered his country to be ready to use its nuclear weapons at any time and to turn its military posture to “pre-emptive attack” mode in the face of growing threats from its enemies, state media said on Friday.

The comments, carried by the North’s official KCNA news agency, marked a further escalation of tension on the Korean peninsula after the U.N. Security Council on Wednesday imposed harsh new sanctions against the isolated state for its nuclear program.

Kim made the comments as he supervised military exercises involving newly developed rocket launchers, KCNA reported. It did not mention the date of the drills but said the new weapons had South Korea within range.

South Korea’s defense ministry said on Thursday North Korea launched several projectiles off its coast into the sea up to 150 kilometers (90 miles) away, an apparent response to the U.N. sanctions.

Kim said North Korea should “bolster up (its) nuclear force both in quality and quantity” and stressed “the need to get the nuclear warheads deployed for national defense always on standby so as to be fired any moment,” KCNA quoted him as saying.

“Now is the time for us to convert our mode of military counteraction toward the enemies into an preemptive attack one in every aspect.”

“Under the extreme situation that the U.S. Imperialist is misusing its military influence and is pressuring other countries and people to start war and catastrophe, the only way for our people to protect sovereignty and rights to live is to strengthen the quality and quantity of nuclear power and realize the balance of power,” Kim said, according to KCNA.

“We are aware of the reports. We are closely monitoring the situation on the Korean Peninsula in coordination with our regional allies,” the Pentagon said in response to Friday’s news. “We urge North Korea to refrain from provocative actions that aggravate tensions and instead focus on fulfilling its international obligations and commitments.”

Fresh sanctions

Earlier this week, the U.N. Security Council voted to impose an array of sanctions against North Korea because of that nation’s recent nuclear test and missile launch, both of which defied international sanctions.

The U.N. resolution that brought about the sanctions aims to cripple the economic factors that fuel North Korea’s nuclear and ballistic missile programs.

The North Korean state news agency blasted the sanctions as “unprecedented and gangster-like.”

The “political and economic pressure and military aggression on the DPRK have gone to a grave phase that can no longer be overlooked,” KCNA said.

China reiterated its opposition on North Korea developing nuclear weapons.

Fu Ying, a spokeswoman for China’s Parliament, said it will abide by the Security Council sanctions, but she highlighted the need for six-party talks to resolve the issue.