The US has reimposed economic sanctions against a Venezuelan state-owned mining company and says it could go on to reimpose further sanctions on the country’s oil and gas sector after Venezuela’s Supreme Court barred main opposition candidate Maria Corina Machado from running for president last week.

The US Treasury on Monday revoked General License 43, which had authorized dealings with mining conglomerate CVG-Minerven. The Treasury said US companies have until February 13 to wind down transactions that were previously authorized by that license.

While US economic sanctions against the mining company are unlikely to cause significant damage to the Venezuelan economy, the US State Department has crucially signaled it intends to renew oil and gas sanctions from April 18, if there’s no progress between Venezuela’s authoritarian president Nicolas Maduro and the opposition “particularly on allowing all presidential candidates to compete in this year’s elections,” it said in a statement.

Venezuela’s Vice President Delcy Rodríguez described the move as “blackmail” on Tuesday, warning that Caracas would stop cooperating in repatriation flights for Venezuelan migrants from the US if Washington’s “economic aggression” intensifies.

Sanctions against Venezuela were first imposed in 2017 and gradually increased as the South American country’s political crisis deepened in the following years.

In October, the Biden administration lifted general economic sanctions targeting Venezuela’s mining and oil industries, in support of an agreement struck in Barbados between Maduro and the opposition to hold free and fair elections in 2024.

But on Friday, the Supreme Court upheld a decision to disqualify Machado, the opposition’s main presidential candidate. The court’s ruling amounts to a repudiation of the agreement, both the opposition and the United States have claimed.

“Actions by Nicolas Maduro and his representatives in Venezuela, including the arrest of members of the democratic opposition and the barring of candidates from competing in this year’s presidential election, are inconsistent with the agreements signed in Barbados last October by representatives of Nicolas Maduro and the Unitary Platform,” US State Department Spokesperson Matthew Miller said Tuesday.

Earlier on Monday, White House’s spokesperson John Kirby had said Maduro had until April to return to the negotiating table and commit to what was agreed last year, including holding free elections where all candidates are allowed to run, or sanctions could be reimposed.

Reinstating oil and gas sanctions could cause substantial damage to Venezuelan exports which are largely dependent on oil, analysts have said. It also has the potential to impact the US domestic gas market because several US companies, including Chevron, operate in Venezuela and Venezuelan crude is regularly exported to refineries in the US Gulf Coast, data from the US Energy Information Administration show.

Machado also commented on Rodríguez’s warning that Venezuela could stop cooperating on repatriation flights, saying, “You can imagine that it breaks my heart to see our people being used in such a hard and unlawful way. I want Venezuelans to come back to our country and to come back freely to our country because they have a future in our land.”