Venezuela's exports of crude and fuel rose in February to their highest since November, vessel monitoring data showed, as the U.S. prepared to terminate a key license that allows oil major Chevron to operate and ship crude from the country.

The move — announced by Trump in a Truth Social post last week — will be a major blow to Venezuela. Chevron produces about a fifth of Venezuela’s crude annually, according to analysts at the Rystad Energy research firm, and losing the ability to export to the U.S. will be a blow to the country’s already floundering economy.

The Trump administration formally revoked on Tuesday the license that allows oil giant Chevron Corp. to sell Venezuelan oil in the United States, giving the U.S. company only 30 days to wind down its operations in the South American country.