The U.S. struck a deal with Venezuela to get majority control of more than 65 billion barrels of oil reserves as the war with Iran roils the global crude trade, President Donald Trump announced Friday.

Trump said in an evening social media post that the deal — which he described the agreement as the biggest oil deal in world history — comes "at no cost to" U.S. taxpayers.

The agreement more than doubles the U.S. oil reserve, according to Trump. Department of Energy data released earlier this month showed oil volumes in the Strategic Petroleum Reserve hit lows not seen since the 1980s.

Trump's deal with Venezuela follows the U.S.' January attack on the South American country. Nicolás Maduro, Venezuela's then-president, and his wife, Cilia Flores, were captured during the strike.

"This Transaction will greatly strengthen the already growing relationship between Venezuela and the United States," Trump wrote in the post.

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