UNITED NATIONS - UN Secretary-General Ban Ki-moon Thursday welcomed the announcement of the governments of Sudan and South Sudan to resume talks in Addis Ababa, Ethiopia, next week.

"The secretary-general welcomes the announcement of the governments of Sudan and South Sudan to resume talks in Addis Ababa next week under the auspices of the African Union High Level Implementation Panel," said a statement issued here by Ban's spokesman.

"The secretary-general encourages the parties to reconvene in an atmosphere of goodwill and calls on them to demonstrate the flexibility necessary to reach agreement on outstanding issues in accordance with the guidance and deadlines set by the African Union Peace and Security Council and the UN Security Council," said the statement.

South Sudan became independent from Sudan in July 2011, six years after the signing of a peace agreement that ended decades of war between the north and south.

However, the peace between the two countries has been threatened recently by clashes along their common border and outstanding post-independence issues that have yet to be resolved.

Tensions increased over recent weeks after South Sudanese forces moved into the oil-producing region of Heglig in Sudan's South Kordofan state before eventually departing, and Sudanese forces bombed the South Sudanese territory.

The statement said the secretary-general reiterated that the United Nations is ready to help the parties implement their agreements and support the mechanisms established by them.

"He stresses the necessity of commencing the work of the Joint Border Verification and Monitoring Mechanism for peace and security along the border and confirms UNIFSA's readiness to immediately support its operations," said the statement.

The UN Security Council established the UN Interim Security Force for Abyei (UNIFSA) in June last year following an outbreak of violence after Sudanese troops took control of Abyei, a border area disputed between South Sudan and Sudan. This led to the displacement of tens of thousands of people in the weeks before South Sudan became an independent state.

Last week, the 15-nation Security Council extended UNIFSA's mandate for another six months, and demanded the two countries finalize the establishment of an administration for the area in line with an agreement signed last year.

In a unanimously adopted resolution in early May, the Security Council determined that the prevailing situation along the border between Sudan and South Sudan constituted "a serious threat to international peace and security."

It called on the two countries to immediately end hostilities and resume negotiations, and voiced its intention to take "appropriate measures" if the parties did not comply.

Earlier this week, UN Resident and Humanitarian Coordinator for Sudan Ali Al-Za'tari said that only 5,000 people have returned to Abyei while more than 100,000 people remain displaced. He noted that it was "high time" for humanitarian staff to have access to Abyei from Sudan.

At present, international humanitarian staff are not able to reach Abyei unless they travel via South Sudan.