North Korea has warned the U.S. that it would take “merciless self-defensive” measures if Donald Trump orders a naval blockade, said North Korea’s Central News Agency (KCNA), citing a spokesman of the Foreign Ministry of the country.

According to KCNA, the North Korean Foreign Ministry said the U.S. would be taking a dangerous step towards nuclear war by enforcing a naval blockade. The Ministry also said that Pyongyang would consider any naval blockade a “wanton violation” of its dignity and sovereignty and “an act of war.”

“The gang of Trump is taking an extremely dangerous and big step towards the nuclear war by recklessly seeking the naval blockade against our country,” the spokesman said.

It is not yet clear what U.S. proposal KCNA was referring to.

According to CNBC, the current situation in the Korean Peninsula is highly tense as North Korea has declined to abandon its missile and nuclear programs. Last month, Pyongyang announced that it had carried out a test of its most advanced ICBM Hwasong-15, capable of carrying a nuclear warhead to any part of the U.S. territory.

In early December, the U.S. and South Korea conducted a joint military exercise named “Vigilant Ace 18.” Pyongyang criticized this joint exercise by two countries, saying such activities would eventually lead to a war.

The Trump administration has repeatedly said that all options in dealing with North Korea are open.

North Korea warns US any sea blockade would be an act of war, vows retaliation https://t.co/8Ayzca9aCW pic.twitter.com/GfIdfLfZrr — Al Jazeera English (@AJEnglish) December 14, 2017

On Thursday, British Foreign Secretary Boris Johnson said this crisis can be resolved in a better way by intensifying the economic sanctions against the isolated state. Johnson’s statement came after his meeting with Japanese Foreign Minister in London.

Amid the tense situation in the region, Chinese President Xi Jinping has said that world leaders need to take proper measures to avoid breaking out of a war in the Korean peninsula. According to the Reuters, Mr. Xi made these comments after his summit talks with South Korean President Moon Jae, who is currently on a state visit to China. Both leaders also agreed to improve bilateral relations between two countries to ensure the long-term stability of their ties.

President XI said China gives much importance to its relations with the Republic of Korea and is always ready to work with the country for the well-being of the citizens of two nations. Xi also stated that both sides must stick to the principle of mutual benefit and support to keep their bilateral relations on the right track.