WASHINGTON (AP) _ This month's surprising election victory for ex-rebels in Nepal could force the Bush administration to deal with a group it has considered a terrorist organization.

The United States faces a dilemma in engaging the Maoists, who gave up a 10-year insurgency in 2006, joined mainstream politics last year and are now set to play a major role in Nepal's government. Washington is interested in maintaining ties with the poor country wedged between growing powers India and China, but it is also treading carefully with a group placed on a U.S. terrorism blacklist for a rebellion in which more than 13,000 people died.

The Maoists have tempered their views since entering the political process. But it is unclear whether the U.S. will remove them from the terror list now that their showing in Constituent Assembly elections makes it certain they will form the backbone of a new government.

They won 217 seats in the 601-seat body, more than double the number of their nearest rival, an election official said Thursday in Katmandu, the capital. The preliminary results also show Nepal's traditional electoral power, the Nepali Congress, in second place with 107 seats.

"The U.S. government was taken by surprise, and they're basically trying to figure things out," said Teresita Schaffer, a former State Department South Asia specialist and U.S. ambassador to Sri Lanka, of the Maoists' election win.

As the United States "contemplates the road ahead, the options are not particularly attractive," said Schaffer, an analyst at the Center for Strategic and International Studies think tank. The Maoists' success "is being received with great uneasiness in the U.S. government."

Walter Andersen, a professor of South Asia studies at Johns Hopkins University's school of international studies, said he was "almost certain" that the United States would not refuse to deal with the Maoists.

The main reason, he said, is that they have gained power in democratic elections.

The Maoists won half the seats for the Constituent Assembly that were up for grabs in direct elections April 10. Although direct elections account for fewer than half the seats in the Assembly, the Maoists are assured a major role in a body that will rewrite the constitution, decide Nepal's political future and govern the country in the interim. On Tuesday, officials said the Maoists' top leaders met to map out a future government for the Himalayan nation they probably will lead.

The United States is not yet saying if the ex-rebels will now be removed from the terror list. State Department spokesman Tom Casey told reporters Monday that "to the extent you have an organization that moves away from violence and terror and participates in a political process and engages in those kinds of legitimate activities, that would certainly, I think, give people an opportunity to at least look again at that situation and that organization." He added that "there's no change in their status" at this point.

The Maoists abandoned their fight for a communist state in 2006 after widespread unrest forced King Gyanendra to cede total power. Their strong election showing appears to remove the threat of disaffected former rebels renewing their armed struggle.

As it considers how to handle the Maoists, the United States will be keen to consult with India, which views Nepal as a strategically important buffer between it and Asia's other power, China, according to Andersen. Economic and political ties between the United States and India are growing, and the United States often takes its cues on events in Nepal from India, he said. India is fighting its own communist insurgency.

Copyright 2008 The Associated Press.