Senate Foreign Relations Cmte Chair Robert Menendez on what he says is 'clearly an invasion' of Ukraine by Russia.
House Minority Leader Nancy Pelosi: Putin's actions result from insecurity about Russia's "diminished role in the world."
Homeland Security chair Rep. Michael McCaul (R-TX) thinks President Obama needs to put more pressure on Vladimir Putin.
Senate Intelligence Chair Dianne Feinstein demands Putin "man up" and take responsibility for Russia's role in MH17 crash.
By CNN's Susan Garraty
In the continuing effort to get at Russian President Vladimir Putin where it hurts the most, the White House is encouraging US business leaders to withdraw from planned participation in the St. Petersburg International Economic Forum to be held later this month in Russia.
White House spokesperson Caitlin Hayden tells CNN's State of the Union that participating in the forum is a choice for American businesses, but the Obama administration is letting companies know it takes a dim view of those who choose to go to St. Petersburg while the crisis in Ukraine continues and economic sanctions are in place.
Chairman of the Senate Intelligence Committee Sen. Dianne Feinstein (D-California) tells Candy that while she has deep concerns, she has "persuasive hope" that Putin will not invade Ukraine.
Former Secretary of State Madeleine Albright cautions that the US should be more wary of Putin's aggression in Ukraine.
Sen. John McCain tells Candy Crowley the U.S. needs to reevaluate its relationship with Vladimir Putin and Russia.