WASHINGTON — The U.S. Senate has passed a measure which “strongly condemns” Russia’s attack on the Ukrainian navy in the Kerch Strait — and called on the president to do likewise.

The upper chamber approved the resolution by unanimous consent late Thursday, hours after Trump announced on Twitter he was canceling a meeting with Russian President Vladimir Putin that had been scheduled for Saturday in Buenos Aires. Trump cited Russia’s failure to return Ukrainian ships and sailors it seized on Sunday.

Trump appeared to have made the decision on the way to the G20 summit in Argentina, tweeting:

“Based on the fact that the ships and sailors have not been returned to Ukraine from Russia, I have decided it would be best for all parties concerned to cancel my previously scheduled meeting in Argentina with President Vladimir Putin.

“I look forward to a meaningful summit again as soon as this situation is resolved!”

U.S. Defense Secretary Jim Mattis said Wednesday that Russia’s seizure of the Ukrainian ships violated a treaty between the two countries and showed that Moscow cannot be trusted.

“When you think that there is a treaty between the two countries ... it just shows that Russia cannot be counted on right now to keep its word,” Mattis said, according to Reuters.

On Sunday, Russian ships fired on and seized three of Ukraine’s artillery ships, wounding six Ukrainian crew members. Russia also seized 24 crew members in the incident, which occurred between the Azov Sea and Black Sea.

Lawmakers from both sides of the aisle have since pressured Trump to lead a response, with sanctions or otherwise. Earlier in the week Trump seemed reluctant to blame Russian aggression in the incident, saying: “We do not like what’s happening either way.”

“We have to be clear and unequivocal because I think we’re being tested — not just us but the [European Union] and others interested in the rule of law,” Sen. Rob Portman, R-Ohio, said Wednesday.

“It’s important that NATO and the United States speak with one voice. It should be multilateral, not just us, and I would hope the EU should join us,” Portman said, who co-chairs the Senate Ukraine Caucus.

Portman said the administration needs to “speak out forcefully, and they have, to a certain extent.”

The resolution was sponsored by Sens. Ron Johnson, R-Wis., and Chris Murphy, D-Conn., the chairman and ranking member of the Senate Foreign Relations Committee’s Subcommittee on Europe and Regional Security Cooperation.

In it, the Senate calls on the Trump administration “to implement an all of government approach to forcefully express opposition [to the attack] at every opportunity.”

It also “urges members of the international community to unite in opposition to the actions of the Government of the Russian Federation in the Kerch Strait, as they infringe upon fundamental principles of international law affecting all nations.”

The Kremlin, the resolution reads, must “immediately release all Ukrainian crew members and vessels and to cease its harassment of Ukrainian and international shipping transiting the Kerch Strait.”

The Senate also accuses Moscow of “destabilizing for the entire region” and inviting further escalations. The upper chamber also reaffirmed support for Ukraine’s people and territorial integrity.

The Senate Armed Services Committee’s top Democrat, Sen. Jack Reed, on Tuesday called on Trump to cancel the meeting with Putin, announce new sanctions against Russia, and call for the immediate return of the vessels and crewmen, “instead of giving Putin a free pass.”

Joe Gould was the senior Pentagon reporter for Defense News, covering the intersection of national security policy, politics and the defense industry. He had previously served as Congress reporter.

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