WASHINGTON D.C.: The U.S. has threatened to stop the opening of the Nord Stream 2 gas pipeline to Western Europe if Russia invades Ukraine.

Additionally, officials in Berlin said the project could face sanctions if Russia attacks, and Western allies announced they will target Russia’s economy if it invades Ukraine. Moscow, however, denies it is planning an attack.

“I want to be very clear, if Russia invades Ukraine one way or another, Nord Stream 2 will not move forward,” said US State Department spokesman Ned Price.

But, he added, that he was “not going to get into the specifics” of how it would be stopped, and it remains unclear whether the U.S. has the power to cancel the project.

“We will work with Germany to ensure it does not move forward,” Price said.

Meanwhile, Germany said it would not rule out imposing sanctions on the project, with the country’s foreign minister, Annalena Baerbock, telling parliament that Western allies were “working on a strong package of sanctions,” including those related to Nord Stream 2.

However, she said she would prefer to “continue the dialogue” with Moscow.

The pipeline, covering 760 miles, has taken five years to build at a cost of $11 billion, would run under the Baltic Sea and double Russia’s gas exports to Germany.

In November, regulators said the pipeline does not comply with German law and suspended its approval.

Major European businesses have invested heavily in Nord Stream 2, but many groups object to it, including environmentalists, who question how it will fit in with German efforts to cut emissions and tackle climate change.

Local and foreign politicians also expressed their concern that it could increase Europe’s dependence on Russian gas.

Ukrainian President Volodymyr Zelensky previously described the pipeline as a “dangerous geopolitical weapon.”

The threats over Nord Stream 2 came after the U.S. rejected Russia’s key demand to legally prevent Ukraine from joining NATO, while offering proposals that constitute a “serious diplomatic path forward” to Moscow.

President Vladimir Putin is currently assessing the proposals, his spokesman said.

U.S. Secretary of State Antony Blinken said the document containing the proposals had clear “core principles,” including Ukraine’s sovereignty and its right to be part of NATO, if it chooses.

Russia’s foreign minister Sergei Lavrov said the formal response does not address Russia’s “main concern” about NATO’s expansion.