North Korea has described the latest UN sanctions imposed on the country as an "act of war".
The foreign ministry said the measures were tantamount to a total economic blockade, the official KCNA news agency reported.
It added that strengthening North Korea's deterrence was the only way to frustrate the US.
The UN Security Council imposed the new sanctions in response to Pyongyang's ballistic missile tests.
The US-drafted resolution includes measures to slash North Korea's petrol imports by up to 90%.
North Korea is already subject to a raft of sanctions from the US, the UN and the EU.
What did the North Korean statement say?
It described the latest UN sanctions "as a violent breach of our republic's sovereignty and an act of war that destroys the peace and stability of the Korean peninsula and a wide region.
"The United States, completely terrified at our accomplishment of the great historic cause of completing the state nuclear force, is getting more and more frenzied in the moves to impose the harshest-ever sanctions and pressure on our country.
"We will further consolidate our self-defensive nuclear deterrence aimed at fundamentally eradicating the US nuclear threats, blackmail and hostile moves by establishing the practical balance of force with the US."