United Nations, Oct 21, SPA -- Secretary-General Kofi Annan told Eritrea's president it was critical that the northeast African nation reverse its ban on U.N. helicopter flights vital for peacekeepers, a U.N. spokesman said on Friday. Eritrea on Oct. 5 banned helicopters from flying in its airspace, reducing the capacity of the 3,300-strong U.N. Mission in Ethiopia and Eritrea to monitor military movements, resupply troops and conduct emergency medical evacuations. "It is critical that these restrictions be lifted, irrespective of political issues and considerations," spokesman Stephane Dujarric said, quoting from a letter Annan wrote to Eritrean President Isaias Afewerki. Annan said the ban severely inhibited the U.N. mission, known as UNMEE, from carrying out its mandate to monitor a security zone along the frontier where Ethiopia and Eritrea fought a two-year border war, Dujarric said. The war ended in late 2000 and cost 70,000 lives. The letter also expressed concern over restrictions placed on humanitarian operations in Eritrea, where 2.3 million people face a food crisis, according to a report of Reuters. --SPA 1452 Local Time 1152 GMT www.spa.gov.sa/297893