By Susannah Price
BBC correspondent at the United Nations
The UN Security Council has decided to pull US, Canadian and European staff serving in the peacekeeping mission in Eritrea out of the country on Thursday. Some 180 personnel, who are military observers and civilians, will be temporarily relocated to Ethiopia.
The UN peacekeepers are expected to leave on Friday
The move follows Eritrea's demand that the UN staff should leave by Friday.
Tensions along the border between Ethiopia and Eritrea have risen with reports of troop movements on both sides in recent months.
Most of the UN peacekeepers monitoring the border following a war between the two countries that ended in 2000 are from Asian and African countries and these will stay.
'Sign of frustration'
The UN Security Council members said in a unanimously agreed statement, they had decided to move the staff out of Eritrea temporarily in the interest of their safety and security.
Dec 2000: Peace agreement
Apr 2002: Border ruling
Mar 2003: Ethiopian complaint over Badme rejected
Sep 2003: Ethiopia asks for new ruling
Feb 2005: UN concern at military build-up
Oct 2005: Eritrea restricts peacekeepers' activities
Nov 2005: UN sanctions threat if no compliance with 2000 deal
The members strongly condemned what they called Eritrea's unacceptable actions and restrictions on the peacekeeping mission and warned it could have implications for the operation's future.
Diplomats said the move did not mean they were caving in to Eritrea, which last week ordered the Canadian, American and European staff members to leave the country.
Eritrea's demand is widely seen as a sign of frustration that little has been done by the international community to force Ethiopia to leave the border town of Badme.
This was given to Eritrea by the Boundary Commission, set up under a peace agreement between the two countries.
The Security Council also emphasised the need for progress in implementing this Boundary Commission's decision.
US ambassador to the UN, John Bolton, said Eritrea was acting unacceptably but that they also needed to focus on Ethiopia's lack of compliance.