After returning from a trip to Ukraine, a bipartisan group of U.S. senators said they want Congress to act on new sanctions on Russia as negotiations continue and the U.S. presses for a path toward a settlement. The delegation said it toured Odesa, an economically important Black Sea port that has been targeted by Russia during the nearly four years since the war began.

The trip included Democratic Sens. Jeanne Shaheen, Chris Coons, Richard Blumenthal and Sheldon Whitehouse. Republican Sen. Thom Tillis had planned to join the Ukraine visit but was unable to participate for personal reasons.

Shaheen said in remarks to reporters that one message the senators heard throughout the trip was that Ukrainians want peace, but they want a deal that preserves Ukraine’s sovereignty and recognizes the importance of the country’s territorial integrity. Coons said the lawmakers’ conversations with European counterparts and Republican colleagues helped them leave Munich with a shared determination to keep supporting Ukraine.

The senators’ push comes at a tense point in the conflict and during a diplomatic window in which delegations for the two sides were meeting in Switzerland for two days of U.S.-brokered talks. Neither side appeared ready to move on issues such as territory and future security guarantees, the senators said, and they argued that sanctions could increase leverage ahead of a U.S.-set June deadline for settlement.

Whitehouse said the pressure was meant to address what he described as a lack of trust in Russia’s approach to negotiations. He said, “Literally nobody believes that Russia is acting in good faith in the negotiations with our government and with the Ukrainians,” adding that “pressure becomes the key.”

The senators said legislation to impose tougher sanctions has stalled in Congress for months. They cited a broad Senate package under consideration that would allow the Trump administration to impose tariffs and secondary sanctions on countries that purchase Russia’s oil, gas, uranium and other exports, which they said are crucial to financing Russia’s military.

They also pointed to more targeted proposals that the Senate Foreign Relations Committee has advanced. Those would, the senators said, include sanctions aimed at China’s support for Russia’s military, steps to commandeer frozen Russian assets, and measures to go after what is known as Russia’s “shadow fleet” of oil tankers used to circumvent sanctions already in place.

Republican Sen. Lindsey Graham, a co-sponsor of the sweeping sanctions and tariff legislation, said during the Munich Security Conference that Senate Majority Leader John Thune committed to bringing the sanctions bill to the floor once it had the 60 votes needed to move ahead in the Senate. Graham called the legislation “a game changer,” saying “President Trump has embraced it. It is time to vote.”

Blumenthal said the sweeping package has bipartisan support and described it as a “very tough sledgehammer of sanctions and tariffs,” while noting that lawmakers still need to work out remaining details. He said Democrats and some Republicans oppose the tariff-related approach tied to President Donald Trump’s campaign to impose tariffs broadly in pursuit of trade deals and more manufacturing in the U.S.

The senators also said the House has its own fight over the tariff components. In that chamber, Democrats oppose the tariff provisions, and the senators said a bipartisan group led by Rep. Brian Fitzpatrick has proposed separate legislation that makes it harder for Trump to waive sanctions but drops the tariff provisions.

They said another measure led by Rep. Gregory Meeks would bolster U.S. military support for Ukraine by $8 billion, and that Democrats need one additional Republican to support an effort to force a vote on that bill.

Once back in Washington, the senators said they planned to outline how U.S. businesses based in Ukraine have been attacked by Russia. They also said the push for sanctions is paired with an effort to press the administration to send more U.S. weapons to Ukraine, with Blumenthal saying, “Putin understands weapons, not words.”