“As a matter of principle, the EU opposes the imposition of sanctions against EU companies conducting legitimate business,” an EU spokesman said.

The sanctions were signed off by US President Donald Trump on Friday, targeting companies building the nearly US$11 billion Nord Stream 2 pipeline under the Baltic Sea.

The project aims to double deliveries of Russian natural gas to Europe’s leading economy, Germany, but US lawmakers warn it will enrich a hostile Russian government and vastly increase President Vladimir Putin’s influence at a time of heightened tension across the continent.

The European Commission, the bloc’s executive, is now analysing the likely impact of the US sanctions.

“The Commission’s objective has always been to ensure that Nord Stream 2 operates in a transparent and non-discriminatory way with the appropriate degree of regulatory oversight,” the spokesman said.

The spokesman noted that EU rules on pipelines to the bloc, which came into force in May, have been recognised by the US.

The US sanctions came just days after the EU brokered a deal between Russia and Ukraine on the transit of gas to Europe ahead of a looming New Year deadline.

Some 18% of the EU’s annual natural gas consumption comes from Russia via Ukraine, putting additional pressure on EU officials to broker a deal.