Hurricane Katrina victims in New Orleans being evacuated by military helicopter

European Union officials say transportation and other logistical problems are holding up some of the massive amounts of humanitarian aid European countries have offered to victims of Hurricane Katrina.

In Brussels Tuesday, a spokeswoman for the European Commission said a Swedish plane loaded with food and water treatment tools was ready to take off, but had not received approval from Washington to enter U.S. airspace.

She said EU authorities have suggested to the Bush administration that aid could flow more easily if it was placed aboard military planes at U.S. air bases in Europe.

More than 20 countries have offered emergency aid teams, tents, meals, water and aircraft to help in the massive relief effort.

Meanwhile, U.S. officials say all aid flights from abroad will be directed to an Air Force base in Arkansas, before being sent to the devastated U.S. Gulf Coast.