Senate Foreign Relations Committee Chairman Bob Corker (R-Tenn.) accused Senate Democrats on Wednesday of being “Russia’s best friend” for refusing to approve a measure making technical corrections to a bill on sanctions for Russia and Iran until they get assurances that the House will pass the measure.

Senate Democrats do not trust that House Republican leaders will put the measure on the floor in its current form, according to a senior Senate Democratic aide, who explained that many of them suspect House leaders are using the procedural complaint as a delaying tactic or an excuse to alter the bill in deference to President Trump, whose administration opposes the measure.

The bill steps up sanctions against Iran for its ballistic missile tests and against various sectors of the Russian economy for Moscow’s aggressive moves in Ukraine and Syria, and charges that Russia meddled in the 2016 U.S. elections. The Senate passed a version of the bill last week, 98 to 2, before House leaders complained that the bill had the potential to affect government revenue and constitutionally had to be tweaked before they could take it up.

The measure is controversial for the White House because of a provision giving Congress the right to review any attempts the president makes to change the Russia sanctions before he can go ahead — restraining him, in effect, from rolling back existing sanctions against Russia.

It’s in that section of the bill that the House’s technical complaint arose — and although members of both parties say they have found an acceptable fix, some Democrats are still suspicious.

Corker, however, has lost his patience with Democrats.

“It’s a ridiculous position to take that you’re not going to let our bill go to the House in an appropriate manner until you know exactly how the House is going to deal with a bill that we’ve passed. That is a losing strategy,” he said. The added delay, Corker continued, “is actually accommodating Russia.”

House leaders have not offered to take up the sanctions bill without the Senate acting first, although House committee leaders have indicated they are eager to move ahead with the legislation. In an appearance on Fox News on Wednesday, House Foreign Affairs Committee Chairman Edward R. Royce (R-Calif.) said: “Our goal is to pass this measure as soon as possible. We need to send this message to Putin and to Russia that there will be consequences.”

Not all Senate Democratic leaders seem worried that the House won’t make good on its word.

“We’d love to see them do it, we want to get them into a position where they can do it,” said the committee’s ranking Democrat, Benjamin L Cardin (D-Md.), who added that “there was never a request for a commitment.”

Cardin speculated that the Senate could repass the new version of the sanctions bill by week’s end, cuing it up for the House to vote on the measure shortly after Congress’s week-long Independence Day recess.