The EU already buys the lion's share of U.S. oil and gas exports, according to U.S. government data. No extra volumes are currently available unless the United States raises output or volumes are re-routed from Asia, another big consumer of U.S. energy.
"I told the European Union that they must make up their tremendous deficit with the United States by the large-scale purchase of our oil and gas," Trump said in a post on Truth Social.
"Otherwise, it is TARIFFS all the way!!!," he added.
The European Commission said it was ready to discuss with the president-elect how to strengthen what it described as an already strong relationship, including in the energy sector.
"The EU is committed to phasing out energy imports from Russia and diversifying our sources of supply," a spokesperson said.
The United States already supplied 47% of the European Union's LNG imports and 17% of its oil imports in the first quarter of 2024, according to data from EU statistics office Eurostat.
Trump has vowed to impose tariffs on most if not all imports, and said Europe would pay a heavy price for having run a large trade surplus with the U.S. for decades.
The EU has steeply increased purchases of U.S. oil and gas following the block's decision to impose sanctions and cut reliance on Russian energy after Moscow invaded Ukraine in 2022.
The United States has grown to become the largest oil producer in recent years, meeting a fifth of global demand. It exports all the crude it cannot consume at home.
U.S. crude exports to Europe stand at around two million barrels per day, representing over half of U.S. total exports, with the rest going to Asia.
The Netherlands, Spain, France, Germany, Italy, Denmark, and Sweden are the biggest importers, according to the U.S. government data.
"Europe is taking close to its maximum capacity for U.S. crude, meaning there is little scope for stronger imports next year," said Richard Price, oil markets analyst at Energy Aspects.
He also said refinery closures in Europe in 2025 won't help increase imports and meet Donald Trump’s demands.
