Sen. Kelley Ayotte (R-N.H.) said there should be “serious consequences” for the downed Malaysian Airlines jetliner found in eastern Ukraine.

“If either Russia or Russian agents are responsible … there should be serious, serious consequences,” Ayotte said on the Senate floor Thursday. “Vladimir Putin and the Russians have been responsible for fomenting the violent situation in eastern Ukraine.”

Ayotte said that the flight manifest revealed that 23 Americans were on the flight that some are saying was shot down by Russian separatists. Nearly 300 people who were on the flight are dead.

“I offer my thoughts and prayers to the families of the victims,” Ayotte said.

Ayotte said an investigation has not yet revealed who or what was responsible for the incident but that if pro-Russian separatists were responsible, Putin should withdraw all support to the separatists in Ukraine.

“Putin could end the violence in eastern Ukraine in moments,” Ayotte said. “He’s responsible for that violence and I would call on him to stop supporting these separatists.”