Senators in both parties are itching to move a bipartisan Russia sanctions package as fighting escalates in the region, but Republicans are waiting on a green light from President Trump.

The effort to pass a robust sanctions package is hitting high gear. Trump and his allies are sounding a considerably more negative tone about Russian President Vladimir Putin, who has shown few signs of slowing down his battle against Ukraine. Some of Trump’s closest allies, including Sen. Lindsey Graham (R-S.C.), are pushing hard to more aggressively target Putin.

And both a stunning operation by Ukraine and an escalation of attacks by Russia are giving more senators the impetus to act.

But while Trump’s grown more vocal about Putin’s unwillingness to move toward a peace deal, he has declined to throw in his lot with the sanctions bill, which has more than 80 co-sponsors in the upper chamber — effectively keeping it on ice for the time being.

“We’re working with the White House. … We are prepared to move forward as soon as they feel like the timing is right. They’re leading,” said Sen. Markwayne Mullin (R-Okla.), who, along with Graham, has had ongoing talks with Trump about the sanctions bill. “We don’t want to get in front of the White House.”

“We don’t want to interfere in the middle of negotiations. … If we have to do this to get their attention, we most definitely will. We’re 100 percent willing and able to move forward with it,” Mullin continued. “It doesn’t do us any good if we pass it in the House, pass it in the Senate and then the president is like, ‘Hold on a second guys.’ It puts him in a bad position [and it] puts us in a bad position.”

Senate Majority Leader John Thune (R-S.D.) told reporters that the bill could hit the floor during the current four-week work period. 

“[The White House is] still hopeful they’ll be able to strike some sort of a deal, but … there’s a high level of interest here in the Senate on both sides of the aisle in moving on it,” he said. “I think a genuine interest in doing something to make clear to Russia that they need to come to the table … I think that would have a big impact.”

The package in question would implement some of the harshest sanctions possible on some of Moscow’s top trading partners, including a 500 percent tariff on nations that purchase oil, gas, uranium and other goods from Russia.

China and India are Russia’s biggest customers for those items, accounting for 70 percent of Russia’s energy exports. 

Graham, one of the leading proponents of the legislation, labeled it as “the most draconian bill I’ve ever seen in my life in the Senate.” He also told The Associated Press that he crafted it in coordination with Trump’s advisers and last week said he expected the Senate to start moving the bill this week. 

Nevertheless, Trump has remained noncommittal, even though he has increased his criticism of Putin in recent weeks.

“I don’t know. I’ll have to see it,” he said on Friday when asked about the proposal.

The push comes on the heels of Graham’s visit to Kyiv, where he and Sen. Richard Blumenthal (D-Conn.) met with Ukrainian President Volodymyr Zelensky, and then Paris, where Graham spoke with French President Emmanuel Macron to discuss the latest state of play in the war. 

According to the South Carolina Republican, the only steps Putin is taking in the coming months to end the war is trying to defeat the Ukrainians. 

“We saw credible evidence of a summer or early fall invasion, a new offensive by Putin,” Graham told The Associated Press. “He’s preparing for more war.”

Russian, Ukrainian and U.S. officials convened in Istanbul for a second round of peace talks on Monday, where the two warring nations agreed to trade thousands of dead and seriously injured troops. However, there were no signs of progress toward concluding the 3-year-old war. 

The talks took place only days after Ukraine launched a stunning drone offensive that destroyed 40 Russian warplanes at air bases across the country. The total represents one-third of the Russian bomber fleet, and the attack happened after Ukraine smuggled 117 drones deep into Russia in an operation that took 18 months of planning.

Russia, meanwhile, launched a heavy attack on Ukraine on Sunday. According to the Ukrainian air force, Russia launched 472 drones against Ukraine, marking the highest total since the beginning of the war. 

The intense back-and-forth in recent days is inspiring more lawmakers to push for action. 

“I hate to say that I’m glad the president is seeing … Putin for the evil murderer that he is, but now we have to have a consequence for it,” Sen. Thom Tillis (R-N.C.) said, adding that he would vote for the sanctions package “in a heartbeat.” 

While Republicans wait on word from the president, Democrats have no such patience.

“The single best thing President Trump can do to strengthen Ukraine’s hand right now is to show that the U.S. stands firmly behind them and squarely against Russia. But so far, Trump has not done that,” Senate Minority Leader Chuck Schumer (D-N.Y.) said on the floor Monday. 

“Where is Donald Trump’s backbone? Where is his conviction? Where’s that toughness he likes to project?” Schumer asked. “Frankly, senators from both sides of the aisle are getting tired of Donald Trump’s wishy-washy approach to Putin. If Donald Trump won’t stand up to him, the Senate must.”

The New York Democrat also called the sanctions package a “hammer blow” to Moscow.

“It’s very much needed, and it’s needed now,” he added.