HOUSTON (Reuters) -A vessel chartered by Chevron ( CVX ) carrying some 300,000 barrels of Venezuelan oil was set to start discharging at a Venezuelan port on Thursday, according to shipping data and a source.

It would be the last tanker to return its cargo following state company PDVSA's order to return the crude amid payment uncertainty related to U.S. sanctions.

The Marshall Islands-flagged vessel, Dubai Attraction, on Thursday entered a berth in Amuay terminal, Venezuela, to start discharging the cargo it originally intended to export, LSEG shipping data showed.

Chevron ( CVX ) and PDVSA did not immediately reply to requests for comment.

Venezuela's Vice President Delcy Rodriguez, who is also the OPEC country's oil minister, has blamed the U.S. measures for the issue, saying they prevented Chevron ( CVX ) from paying for the oil.

Venezuela's oil exports fell almost 20% in April to 700,000 barrels per day, the lowest in nine months, due to the cargo cancellations. Chevron's ( CVX ) exports of Venezuelan crude to the U.S. plummeted 69% to some 66,000 bpd due to PDVSA's measures.

Some tankers Chevron ( CVX ) had chartered to move crude from Venezuela to the U.S. were marketed for spot contracts elsewhere, sources said last week. This signaled that Chevron ( CVX ) does not expect to load all the cargoes it typically ships from Venezuela even if it eventually finds a way to resolve the disagreement with PDVSA.

In March, President Donald Trump's administration revoked a license issued in 2022 by the U.S. Treasury Department for Chevron to operate in Venezuela. The May deadline was granted to wind down operations and oil exports.

The same deadline was granted to other partners of PDVSA, including Eni, Repsol, Maurel & Prom and Reliance Industries, to wind down oil cargoes bound for Europe and Asia.

Tankers chartered by trading house Vitol were loading and discharging normally at Venezuelan ports, according to the data and documents, while vessels chartered by Reliance Industries for India delivery and Maurel & Prom for Europe departed on schedule last week, ahead of the May 27 deadline to wind down cargoes and operations.