UN Secretary General Kofi Annan is visiting the Horn of Africa in a new initiative to kick start the stalled Ethiopian Eritrean peace process.
The UN border presence is extremely costly
Some 4,000 UN peacekeepers patrol the Eritrean-Ethiopian border following the war which ended in 2000.
"Our intention is not to stay here forever," Mr Annan said in Asmara, the Eritrean capital.
His trip comes before Tuesday's African Union summit at which the Eritrean- Ethiopian issue is likely to feature.
The two sides appear to be no nearer reaching a lasting settlement since they ended hostilities.
They had both agreed to honour the decisions of a border commission established at The Hague.
Ethiopia's government however refused to implement the commission's decision last year, saying it would not split families and settlements.
Eritrea has asked the international community to take some form of action against Ethiopia.
"The international community is very worried and the secretary
general himself is worried to see that things are not advancing as
he would have liked to see them advance," said the head of UN
peacekeeping operations, Jean-Marie Guehenno.
Mr Annan met Eritrean President Isayas Afewerki on Saturday before flying on to the Ethiopian capital Addis Ababa.
The UN border operation costs $200m (£109m) a year.