If Mr. Snowden and his supporters try to arrange for a private jet, could his benefactors afford one big enough to make the nearly 16-hour flight without refueling, to avoid stopping in a country that would be likely to seize him at the request of the United States? And if a private or government plane is sent to pick him up, would it face the same airspace restrictions that forced the plane of President Evo Morales of Bolivia to land in Vienna on his way home from a conference in Moscow last week?

Mr. Morales, still fuming over the diversion of his aircraft, said Saturday that Bolivia would also grant Mr. Snowden asylum “if he asked for it.” Mr. Morales, whose openness to sheltering Mr. Snowden apparently led to the false conclusion that he had smuggled Mr. Snowden onto his airplane, said the decision on asylum was now intended as retaliation.

“As a fair protest” against the United States and Europe, “we are going to give him asylum if he asks us for it, that American pursued by his countrymen,” Mr. Morales said at a public appearance in a Bolivian village, according to local news reports. “We are not afraid.”

Mr. Morales did not say if Bolivia had received a request from Mr. Snowden, who has apparently applied for shelter in more than two dozen countries. Most of those requests have been rejected. Nicaragua’s president said his country had received a request and would grant it “if circumstances permit it.”

State Department officials have been in touch with each of the Latin American nations that have expressed a willingness to harbor Mr. Snowden, the senior administration official said Saturday, and have urged them to expel him if he arrives. But the official, who spoke on the condition of anonymity to talk about diplomatic matters, conceded that the United States already had poor relations with these countries, and while those ties would worsen should Mr. Snowden receive protection, it remained unclear what the United States would do.