Sen. Charles Schumer is demanding harsh penalties on Ecuador if the country provides a safe haven to whistle-blower Edward Snowden, who faces espionage charges for leaking documents about the government's secret surveillance of phone records and Internet data.
Snowden, 30, is said to be hiding out in a Moscow airport, with intentions to apply for asylum in Ecuador.
Speaking outside of the United Nations on Sunday, Schumer said if Snowden's request is granted, the U.S. government should cut economic aid and suspend business visas.
"If you harbor Edward Snowden, there will be significant consequences. And whatever political benefit the leader of Ecuador thinks he will get by granting Snowden asylum, it will be far outweighed by the damage done to Ecuador's economy," Schumer said.
President Rafael Correa of Ecuador said Vice President Joe Biden called him on Saturday and requested asylum not be granted.
Officials in Ecuador have said they cannot consider an asylum request until Snowden arrives in Ecuador or one of the country's embassies.
While Snowden waited for Ecuador's decision, another high-profile leaker spoke out Sunday on Snowden's behalf from his own Ecuadorian hideout.
Julian Assange, the founder of Wikileaks, appeared on ABC's "This Week" to talk about Snowden's situation.
He spoke from the Ecuadorian embassy in London, where he has been living for more than a year to avoid being extradited to Sweden to face a sexual assault allegation.
He said he has a "personal sympathy" for Snowden and said Wikileak's legal team has been in touch with him to offer support.
"He is a hero. He has told the people of the world and the United States that there is mass, unlawful interception of their communications far beyond anything that happened under Nixon," Assange said.
Assange also criticized Biden for speaking with Ecuador's president about the possibility of asylum, saying it is "unacceptable" that Biden tried to "pressure" the Ecuadorian leader.