Sen. Bob CorkerRobert (Bob) Phillips CorkerLawmakers push for House floor debate on war authorization Pressure rising on GOP after Trump–DOJ fight’s latest turn Corker turns downs Trump's offer to be ambassador to Australia MORE (R-Tenn.) slammed President Obama for not following through on threats of increasing sanctions against Russia for its invasion of Ukraine.

“President [Vladimir] Putin is only emboldened by empty rhetoric, so it is time for the administration to back up their talk by immediately putting in place tough sanctions against Russian banks and energy companies,” Corker said Friday.

Obama has said he's "teed up" more sanctions but wants to make sure European allies are on board first.

After Russia annexed Crimea, Congress passed an aid package for Ukraine that included sanctions against some Russian leaders. Lawmakers are calling for further action because Russian President Vladimir Putin is now interfering in eastern Ukraine as well.

“Right now, the feeling on the ground is that Putin is more committed to the failure of Ukraine’s struggling democracy than the West is to its success, and only forceful and immediate action like this can begin to change that dynamic,” Corker said.

Corker, who serves as ranking member of the Senate Foreign Relations Committee, also said the United States should work to ensure Putin doesn’t extend his reach into other neighboring countries, such as Moldova and Poland.

“The United States must develop a long-term strategy to counter Russian aggression in Europe since the impact of Putin's interference extends far beyond Ukraine,” Corker said.

Corker just returned from visiting Ukraine during the two-week recess.