BUENOS AIRES, Argentina (AP) — Secretary of State Rex Tillerson says that the U.S. is still considering restricting the sale of oil from crisis-torn Venezuela.

Tillerson said Sunday in Argentina's capital that the U.S. wants "free, fair, and verifiable elections" in Venezuela, and wants to apply enough pressure to end the crisis in the South American country.

But he also said that he wants to find ways to mitigate the negative impact that sanctions would have on U.S. oil companies, Venezuelans and other regional countries that rely on Venezuelan oil.

Venezuela sits atop the world's largest oil reserves and is the third-largest supplier to the U.S.

International pressure has been increasing on Venezuela over the government's decision to push up presidential elections to April under conditions that opponents say overwhelmingly favor President Nicolas Maduro.