Bush argues that the deals are crucial for US companies, allowing them to compete with their foreign counterparts.


Democrats, who will come to power when a new congress begins on January 4, say the deals often favour the US's competitors. They accuse the Bush administration of doing too little to protect Americans from unfair foreign trade practices. In a letter to the administration, leading congressional Democrats have said the Colombian deal does not protect workers' rights.


Bush acknowledged Democratic concerns during a recent trip to Asia.


"We hear voices calling for us to retreat from the world and close our doors to these opportunities," he said in a speech in Singapore, which already has a free trade agreement.


"These are the old temptations of isolationism and protectionism, and America must reject them."


"We hear voices calling for us to retreat from the world and close our doors to these opportunities"

George Bush,
US president
The US trade representative's office said the deal with Colombia, once approved, would make more than 80 per cent of US consumer and industrial exports to Colombia immediately free of duties and improve two-way trade that reached $14.3bn last year.


When Alvaro Uribe, the Colombian president, visited the US congress this month looking to secure congressional backing for the deal, Democrats told him its prospects were sinking.


The deal would be the United States' biggest in the Western hemisphere since the North American Free Trade Agreement in 1994.


Democrats point to claims by the International Labour Organisation that Colombia is the world's deadliest country for labour organisers, with more than 1,200 cases of murder in recent years. Colombia has also been battling drug traffickers and guerrillas.