Khartoum has also set up a committee to implement UN Security Council sanctions against North Korea, the foreign ministry said in a statement.

"Sudan's defence manufacturers have cancelled all contracts signed with North Korea and also ended their relations, direct or through third parties, with North Korea," the ministry said.

"Sudan has also set up a committee to prepare a report on how to implement the international sanctions imposed by the United Nations Security Council on North Korea."

Washington has been stepping up pressure on Khartoum to terminate all its ties with Pyongyang, even though the East African country has had no diplomatic relations with North Korea.

Although Khartoum insisted it had no such ties, it acknowledged Wednesday having signed defence contracts with North Korea.

In October, Washington lifted its decades-old sanctions imposed on Khartoum but kept Sudan on its list of "state sponsors of terrorism" along with North Korea, Iran and Syria.

Sudanese officials have been pushing to remove Sudan from the blacklist, but Washington insists Khartoum must first provide a complete assurance it has all cut relations with nuclear-armed Pyongyang.

North Korea last year rattled the international community with a flurry of nuclear and missile tests.

US President Donald Trump is due to meet with North Korean leader Kim Jong Un on June 12 in Singapore, with Pyongyang's nuclear arsenal topping the agenda.