Ecuador has said US troops must leave their only South American military base used for anti-drug flights after the 10-year lease expires in 2009, the foreign ministry has said.

About 300 US soldiers are stationed at the Pacific base and flights from Manta are responsible for about 60 per cent of US drug seizures in the eastern Pacific, AP reports.

Rafael Correa, the Ecuadorean president, has repeatedly said that Ecuador would not renew the agreement over the base.

Ecuador's foreign ministry said it had formally notified the US embassy of the decision and and the withdrawal of foreign personnel from the Ecuadorean air force base would end in November.

'No alternative base'

US military officials have said that it is not planning to set up an alternative to the base in either neighbouring Colombia or in Peru.

The US government has also previously said that it would respect Ecuador's decision over the future of the base.

A draft constitution backed by Correa and recently approved by a special assembly, abolishes any foreign military bases on Ecuadorean soil.

However, the draft charter must still be approved by voters in a referendum.

Ecuador produces little cocaine itself but is often used as a transit country for drugs sent from Colombia and Peru - the world's top two cocaine producers to the US.