QUITO, Ecuador — Ecuador said Thursday it is renouncing tariff benefits on hundreds of millions of dollars in trade that are up for renewal by the U.S. Congress.

The announcement by Communications Minister Fernando Alvarez comes at a moment when Ecuador faces U.S. pressure to avoid granting asylum to National Security Agency leaker Edward Snowden. Alvarez told a news conference that the trade deal had become "a new instrument of blackmail.

"In consequence, Ecuador unilaterally and irrevocably renounces said preferences."

The program, initially meant to help Andean countries aiding in the fight against drugs, was facing an uphill fight for renewal. Alvarado did not explicitly mention a separate effort to win trade benefits under a presidential order.

Alvarez said his country "does not accept threats from anybody, and does not trade in principles, or submit to mercantile interests, as important as they may be."

Ecuador has been lobbying for continuation of reduced tariffs on hundreds of millions of dollars' worth of trade in products such as cut flowers, artichokes and broccoli. Nearly half Ecuador's foreign trade depends on the U.S.

With the deal already struggling in Congress, Ecuador's announcement it is considering asylum for Snowden threatened to kill its access to the Generalized System of Preferences, which benefits 127 countries.

On Wednesday, Senate Foreign Relations Committee Chairman Bob Menendez of New Jersey said that if Ecuador grants asylum, "I will lead the effort to prevent the renewal of Ecuador's duty-free access under GSP and will also make sure there is no chance for renewal of the Andean Trade Promotion and Drug Eradication Act."