The head of the Ukraine’s state-owned oil and gas company was in Washington this week to deliver a message to U.S. lawmakers that allowing the completion of the Nord Stream 2 pipeline would be a victory for Russian President Vladimir Putin and a blow to American credibility in Eastern Europe.

“It would mean that this pro-Russian narrative would advance at the expense of the West,” Yuriy Vitrenko, the chief executive officer of Naftogaz Ukraine, said in an interview. “Many people will see that guys like Putin can get their way with the bullying of the West. And it will encourage people like Putin everywhere in the world to use the same kind of tactic.”

Vitrenko, 44, who recently took the helm of the company after a shake-up of top management, also was in the U.S. capital to assure lawmakers that the company was in safe hands. The former CEO, Andriy Kobolyev, was fired after the company reported a loss of 19 billion hryvnia ($684 million) in 2020 that threatened to complicate talks to access a $5 billion international bailout.

Kobolyev has said his firing was illegal and warned of a possible return to an era of mismanagement and corruption at state-owned enterprises.

The company controls gas pipelines that run from Russia to the rest of Europe and the completion of Nord Stream 2, which bypasses Ukraine, is viewed by many in Congress as a threat not only to the economy of Ukraine but to the energy stability of Europe. It is for this reason that Democratic and Republican lawmakers backed sanctions on the pipeline in an attempt to prevent its completion.

Secretary of State Antony Blinken called the completion of the pipeline a “fait accompli” in an appearance before the House Foreign Affairs Committee earlier this week. Vitrenko and others argue there is still a chance the pipeline could be stopped by U.S. sanctions if additional measures are passed as part of any national security-focused legislation moving through both chambers.

“The worst case scenario is not just that we would lose from 2024 a big part of our GDP,” Vitrenko said. “The worst part is that it means a much a higher chance for a full scale war because gas flows through Ukraine into the Europe serves as a deterrent to a full scale war.”

The Biden administration in May waived sanctions on the project’s parent company Nord Stream 2 AG and its chief executive, Matthias Warnig, saying that stopping Nord Stream 2 is a long shot now that the gas pipeline from Russia to Germany is more than 90% complete. Germany backs completing the project and President Joe Biden is trying to rebuild the U.S. relationship with the NATO ally that was strained during President Donald Trump’s time in office.

The decision was met with sharp criticism from Congress. More than 60 House Republicans sent a letter to Biden on Monday saying that completion of Nord Stream 2 “will be a gift to Putin and his efforts to increase geopolitical influence in Europe.”

Senator Jeanne Shaheen of New Hampshire and a bipartisan group of lawmakers have said they would continue to press for sanctions. Shaheen, who recently visited Ukraine, said the Senate was looking at additional sanctions against the pipeline. That is welcome news to Vitrenko, who views the completion of the pipeline as not just an existential threat to Ukraine but to the region as well.

“The worst case scenario is when the Ukrainians, and not just Ukrainians, many Eastern European countries, see basically that the West did not put their money where their mouth was, it would be a great blow to the pro-Western choice of these countries,” Vitrenko said.