Two senators negotiating a package of Russia sanctions have hit “an impasse” over the legislation and said they are now considering votes next week on competing measures.

“We’ve hit an impasse,” said Foreign Relations Chair Bob Menendez, a New Jersey Democrat. “But we’re still trying to work together to think about a way forward.”

Senator Jim Risch of Idaho, the committee’s top Republican, acknowledged they couldn’t resolve outstanding issues and suggested that the Republicans and Democrats could offer their own bills, which would be considered together on the Senate floor in a process known as a “side-by-side” vote.

Such a process would require agreement between Senate leaders and the consent of all 100 senators, which may be difficult given the differences.

“Everybody should get a chance to vote on how they feel about the different aspects of this,” Risch said.

One key obstacle is whether the U.S. should impose secondary sanctions on “all Russian banks” as part of a series of measures that would be taken should Russia invade Ukraine. That would break the U.S.-Europe alliance, Menendez said, and could scuttle any deal on a bipartisan package. Moscow has repeatedly said it’s not planning an incursion into Ukraine.

Menendez and Risch have discussed the package for weeks. In addition to the disagreements over secondary sanctions, the pair have also wrestled with differences over whether the U.S. should preemptively sanction Russia before any incursion as well as how the bill should address the Nord Stream 2 pipeline from Russia to Germany.