A U.S. senator expressed optimism Monday for a free-trade pact between the U.S. and three Andean nations, but said several issues still needed ironing out for the three to gain tariff-free access to U.S. markets.

"There are issues pending, like child labor, unionization and government transparency," said U.S. Sen. Christopher Dodd, a Connecticut Democrat, according to a Dow Jones report. "There is a lot of optimism for the deal," said Dodd, who was accompanied by Rhode Island Republican Sen. Lincoln Chafee.

Dodd and Chafee wrapped up a 48-hour official visit Monday, meeting with national business leaders, government representatives and President Lucio Gutierrez. Ecuador was the final stop in a weeklong South American tour.

Formal negotiations for a U.S.-Andean free-trade deal, involving Ecuador, Peru and Colombia, started last May, but achieving agreement among the four countries has been a painstaking process. Ecuador sponsored a fifth round of talks in October.

Discussions are scheduled wrap up between the countries next month in Cartagena, Colombia. Ecuador's chief negotiator, Cristian Espinoza, said Monday that a trade pact probably wouldn't be signed until December.

Andean negotiators have maintain that U.S. farm subsidies make agriculture competition unfair, while U.S. negotiators have pushed for Ecuador and Peru to resolve long-standing legal disputes with several U.S. businesses in those countries.

"As long as subsidies exist, we should have mechanisms of protection," Ecuadorean Foreign Trade Minister Ivonne Baki said Monday. The three Andean nations already enjoy tariff-free access to U.S. markets for hundreds of products, including asparagus, cut flowers and textiles, through a deal aimed at helping countries on the front line of the drug war. But that deal expires in 2006.