North Korea has slammed the latest UN sanctions and described them as an "act of war" against the hermit kingdom. In a statement issued via the official KCNA news agency, North Korea's foreign ministry lashed out at the US for forcing new restrictions.

"We define this 'sanctions resolution' rigged up by the US and its followers as a grave infringement upon the sovereignty of our Republic, as an act of war violating peace and stability in the Korean peninsula and the region and categorically reject the 'resolution'," it said.

"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."

Through the statement, the country warned that it would further consolidate its "self-defensive nuclear deterrence" which it claims is aimed at fundamentally eradicating the US nuclear threats, blackmail and hostile moves.

"The U.S. should not forget even a second the entity of the DPRK (Democratic People's Republic of Korea) which rapidly emerged as a strategic state capable of posing a substantial nuclear threat to the US mainland," it continued, adding that countries that voted in favour of the sanctions would also be held responsible for the consequences.

"We will make sure forever and ever that they pay a heavy price for what they have done."

On 22 December, the United Nations Security Council voted unanimously to impose tougher sanctions on the Kim Jong-un-led nation in response to its latest intercontinental ballistic missile (ICBM) test.

The resolution aims to restrict access to refined petroleum products and crude oil by issuing an export limit of 500,000 barrels a year to the country. Additionally, North Korean nationals working abroad will be required to return within 24 months, a move that is bound to reduce the flow of foreign currency.

US President Donald Trump and other top officials have made repeated threats about US military action against Pyongyang.

The US ambassador to the UN, Nikki Haley, after the latest round of sanctions, said the steps sent an "unambiguous message to Pyongyang that further defiance will invite further punishments and isolation".

The country is already subject to sanctions from the US, the UN and the EU that have included freezing the assets of individuals and companies linked to its nuclear programme.

Washington has been imposing sanctions on the country since 2008, banning the export of goods and services to the country, with little effect.

In the last two years, North Korea's ruler Kim Jong-Un has conducted more missile tests than his father Kim Jong-Il and his grandfather Kim Il-Sung in 27 years.

In 2017, tensions between the US and North Korea have deepened due to military drills by both sides and both Kim and US President Donald Trump publicly lambasting each other.

North Korea has previously warned that the US would turn into a "sea of fire" after the UN announced a fresh round of punitive sanctions over the country's missile tests.

Kim Jong-un
North Korean leader Kim Jong-Un (R) reacting after the test-fire of the intercontinental ballistic missile Hwasong-14 at an undisclosed location STR/AFP/Getty Images