WASHINGTON — A key U.S. senator said Friday that action on legislation to fight climate change was “impossible” for now because of fierce new opposition to offshore drilling after the Gulf of Mexico oil spill.

“I believe it would be wise to pause the process and reassess where we stand,” Republican Sen. Lindsey Graham said, pouring cold water on predictions that he would eventually support the bill.

Graham withdrew two weeks ago from discussions with Democratic Sen. John Kerry and Independent Sen. Joe Lieberman aimed at crafting a compromise bill to battle greenhouse gas emissions blamed for global warming.

At the time, he cited Democratic plans to move forward on legislation to overhaul U.S. immigration policy, accusing President Barack Obama’s allies of rushing on that front purely for political gain in November mid-term elections.

“In addition to immigration, we now have to deal with a catastrophic oil spill in the Gulf of Mexico which creates new policy and political challenges not envisioned in our original discussions,” Graham said Friday.

The senator, who represents South Carolina, warned that growing Democratic opposition to offshore drilling following the catastrophe imperiled the climate legislation’s political future.

“When it comes to getting 60 votes for legislation that includes additional oil and gas drilling with revenue sharing, the climb has gotten steeper because of the oil spill,” he said. “There are not nearly 60 votes today.”

“We should move forward in a reasoned, thoughtful manner and in a political climate which gives us the best chance at success. Regrettably, in my view, this has become impossible in the current environment,” he said.

His comments seemed to refute Kerry’s recent assertion that Graham would eventually back the legislation even if he was no longer part of the talks.

“A serious debate on energy legislation is significantly compromised with the cynical politics of comprehensive immigration reform hanging over the Senate,” said Graham, a key player on both issues.

Graham said that he disagreed with colleagues who reacted to the spill by saying that a climate change bill was “dead on arrival” if it included an expansion of offshore drilling, seen as a key vote-getter for the proposal.