FILE PHOTO: A North Korean flag flies on a mast at the Permanent Mission of North Korea in Geneva October 2, 2014. REUTERS/Denis Balibouse/File Photo

KHARTOUM (Reuters) - Sudan said on Wednesday it had cut all defence ties with North Korea, in a rare admission that it used to have such ties in the first place.

The announcement came as Washington is locked in a standoff over Pyongyang’s missile and nuclear weapons programmes, and as Sudan, which is still on the U.S. list of state sponsors of terrorism, reels from an economic crisis.

“Sudan’s government would like to affirm that its defence production sector has cancelled all contracts ... with North Korea, and ended all relations, direct or through a third party,” the foreign ministry said in a statement.

It said this came as part of its commitment to the international Non-Proliferation Treaty and sanctions against Pyongyang. It did not say when ties had been severed, or provide details of what they had been.

The United States lifted 20 years of sanctions on Sudan in October, in a move that looked set to help Sudan’s ailing economy, but the country has since plunged into a fiscal crisis, with the Sudanese pound’s value plummeting and no significant increase in foreign investment.

Washington said then that Sudan had made progress fighting terrorism, and that it had secured Khartoum’s commitment not to pursue arms deals with North Korea.

But Sudan remains on the U.S. list of state sponsors of terrorism - alongside Syria and Iran - which means a ban on weapons sales and restrictions on U.S. aid.

Sudan’s economic problems led to widespread protests earlier this year.