BRUSSELS – The European Union is open to discussing trade issues, including energy, with US President-elect Donald Trump, the European Commission said on Friday.

"We are ready to discuss with President-elect Trump how we can further strengthen an already strong relationship, including by discussing our common interests in the energy sector," EU spokesperson Olof Gill told a news conference.

His remarks came after Trump took to the social media platform Truth Social, warning the EU of potential tariffs if the bloc does not increase its purchase of US oil and gas.

"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. Otherwise, it is TARIFFS all the way!!!" Trump wrote.

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The EU appeared to push back, with the spokesperson noting that while the United States runs a goods trade deficit with the bloc, it enjoys a surplus in services.

According to Eurostat data, the United States recorded a 155.8 billion euro ($162.51 billion) trade deficit in goods with the EU last year, alongside a 104 billion euro surplus in services.

Former Italian Prime Minister Enrico Letta criticized Trump's threat in an interview with CNBC, urging the EU to prepare for retaliation. He called Trump's stance "transactional" and "asymmetric," accusing him of conflating issues like energy and tariffs.

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"Considering that the most asymmetric part is the relationship on the financial side, we have to start considering that maybe replying on the financial side could be a solution," Letta said.

Trump's comments rattled the European stock markets, with the pan-European STOXX 600 index closing down 0.88 percent on Friday. Earlier in the session, it had a dip as much as 2 percent.