The United Nations has urged Ethiopia and Eritrea to show restraint near a disputed border, where the countries each have amassed large numbers of troops, a U.N. spokeswoman said Thursday. The Ethiopian and Eritrean troops are within their own territories in defensive positions, but the Ethiopians have come within 20-40 kilometers (12-25 miles) of the frontier in recent months, said Gail Bindley-Taylor Sainte, spokeswoman for the U.N. Mission in Ethiopia and Eritrea. "Our concern is that, if there are troops close to the border, anything that threatens the stability of the temporary security zone is of concern," Sainte told reporters via video-link from the Eritrean capital, Asmara. Ethiopia and Eritrea fought a bloody 2 1/2-year border war that ended in December 2000. The dispute over the 1,000-kilometer-long (621-mile-long) border has never been settled, and 3,800 U.N. peacekeepers currently patrol a 25-kilometer-wide (16-mile-wide) security zone. "We are monitoring the situation very closely, but at the moment the situation remains militarily stable," Sainte said. "We are concerned about the numbers" of troops, she said, without giving any figures.