HANOI -- A leading U.S. researcher said Vietnam's Health Ministry agreed on the need for emergency steps after people living near a former U.S. base where there was a big wartime spillage of the toxic defoliant Agent Orange were found to have "alarmingly high" dioxin levels, Reuters reported on Monday.

University of Texas Professor Arnold Schecter told Reuters he had met Health Minister Do Nguyen Phuong to discuss U.S. laboratory findings showing tests of blood from 24 out of 25 people taken in the southern city of Bien Hoa in 1999 and 2000 showed elevated levels of dioxin, some "alarmingly high".

Schecter, one of the foremost Agent Orange experts after research in Vietnam dating back to 1984, gathered the samples with Hanoi's top researcher Le Cao Dai, executive director of the local Red Cross. Expensive tests were done in the United States.

"The minister of health agreed that what Professor Dai and I had been showing does constitute an urgent public health matter," Schecter said.

"He is going to meet with the minister of science and technology and environment to discuss an emergency medical survey or health survey. That will involve monitoring of blood and food in hotspots and comparison areas."

Schecter said he envisaged hundreds or perhaps thousands of people being tested in 30-50 Agent Orange "hotspots" starting within weeks. He said it would be the biggest survey of its kind ever carried out in Vietnam.

Schecter cautioned that the initiative still needed to be approved by Vietnam's Committee 33, the body in charge of Agent Orange projects under Science Minister Chu Tuan Nha.

The United States sprayed millions of gallons of Agent Orange and other defoliants on Vietnam from 1962 to 1971 to deny communist fighters jungle cover. The chemicals were contaminated by TCDD, the most dangerous form of dioxin.

Washington argues that there is still no solid scientific proof Agent Orange was responsible for a wide range of maladies, including tens of thousands of mental and physical birth defects.