Jean-Marie Guehenno, the French head of the UN department of peacekeeping operations (DPKO), huddled behind closed doors with the council's 15 members to review what Indonesian Ambassador Marty Natalegawa described as a "very disturbing situation."

Earlier, UN deputy spokeswoman Marie Okabe told reporters that Asmara prevented the UN mission monitoring the border dispute between Eritrea and Ethiopia (UNMEE) from relocating some of its personnel and equipment to Ethiopia.

Eritrea's action marked a dramatic escalation of its feud with UNMEE, which has seen Asmara place restrictions on fuel shipments in a move that severely hampers the UN's ability to carry out its mission.

UNMEE is tasked with monitoring the tense Eritrean-Ethiopian border along which a total of some 200,000 troops from both sides are deployed, fueling fears of a new flare-up.

"A number of UNMEE vehicles were stopped by the Eritrean Defense Forces and prevented from crossing the border. In one such case, on 14 February, UNMEE personnel were threatened and the equipment seized," Okabe said.

And she said that the Eritrean commercial company that provides rations to UNMEE Friday announced that "it will no longer be able to fulfill its contractual obligations."

The mission has only a few days of emergency rations left, she said.

"We saw it coming. There had been signals that we were going to be at this juncture because of the obvious lack of cooperation from the Eritrean authorities," Natalegawa said. "But now we'll hear what the secretariat has to say and respond accordingly."

UN chief Ban Ki-moon ordered the relocation after Eritrea ignored his request to lift restrictions on fuel shipments to UNMEE.

"Without the fuel needed to conduct its operations, the mission has been effectively immobilized and rendered unable to carry out its critical functions," a UN statement said Thursday.

Asked why Asmara was blocking the relocation involving up to 1,200 of the 2,000-strong UNMEE, a UN official familiar with the situation replied: "We've seen a variety of responses: everything from they simply have to turn around to they can go through but the equipment has to stay. There seem to be are different responses every time."

Ban "will speak to the Eritreans at the highest level," said DPKO spokesman Nick Birnback. "We are doing everything that we can on our side, but without the consent of the host government it becomes very difficult to envisage a scenario in which our mandate can be implemented."

In a communique, the Eritrean Foreign Ministry said it could not discuss or acquiesce in the "temporary relocation" of UNMEE or some other new "arrangement" that is at variance with the provisions of a peace agreement.

Under the 2000 Algiers peace deal which ended their two-year border war, Eritrea and Ethiopia pledged to accept as "final and binding" a verdict by a UN-backed boundary commission on their dispute.

But the panel dissolved early in December, leaving the frontier delineated only on maps. In its final ruling, it granted Eritrea the border town of Badme, which Ethiopia has refused to accept, saying it split families between the countries.

Eritrea has repeatedly accused its bigger and more powerful neighbor of gearing up for a new war, a claim dismissed by Addis Ababa as a bid by Asmara to divert attention from its internal problems.

Asmara says the Security Council has failed to redress the situation and "ensure the removal of Ethiopian occupation of Eritrean territories in breach of the Algiers Peace Agreement and the UN Charter."

To show its displeasure, it has placed a number of restrictions on UNMEE, including a ban on UN helicopter flights in Eritrea's airspace and its expulsion of UNMEE's North American and European staff.

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