“The pipeline itself is the wedge,” Mr. McConnell said. “That’s the whole point. That’s been Putin’s goal: decoupling Ukraine from Europe and making Europe even more reliant on Russian gas.”
Mr. Cruz’s legislation set off a fierce round of lobbying, squeezing in particular centrist Democrats who have long been supporters of Ukraine. On a Christmas Eve video call with a bipartisan group of more than 20 lawmakers, President Volodymyr Zelensky of Ukraine cast Nord Stream 2 as an existential threat to his country, arguing that the pipeline posed as much risk to Ukraine as the Russian troops amassing on its border, according to four people briefed on the call, who described it on condition of anonymity because they were not authorized to comment on it.
Mr. Zelensky, they said, expressed frustration that the Biden administration had waived sanctions on the pipeline last year. Since then, Mr. Zelensky has promoted Mr. Cruz’s bill on Twitter.
A lobbyist who represents the Ukrainian oil and gas industry, including the state-owned company Naftogaz, reached out this week to the offices of Senate Democrats to urge support for Mr. Cruz’s bill, according to a person familiar with the outreach.
An email sent on Monday to Senate offices by the lobbyist, which was forwarded to The New York Times, included a screenshot of Mr. Zelensky’s tweet, and added the message, “Ukraine Pres. Zelensky calls on all senators to vote in favor of Nord Stream 2 sanctions.”
But the Biden administration marshaled its own forces against the legislation. Responding to a request for a briefing by two Democratic senators, the State Department sent officials to Capitol Hill on Monday to brief lawmakers and dissuade them from supporting the bill. The next day, the issue came up again as senators met with Secretary of State Antony J. Blinken in a closed-door meeting to discuss an upcoming delegation trip to Ukraine.
In an effort to further head off defections, Senator Bob Menendez of New Jersey, the chairman of the Foreign Relations Committee, unveiled on Wednesday a Democratic alternative to Mr. Cruz’s bill that would impose sanctions on top Russian government officials, including Mr. Putin, if Russia engages in or supports “a significant escalation in hostilities or hostile action in or against Ukraine.” It would also provide Ukraine with $500 million in supplemental emergency security assistance in the event that Russia invades.