The situation in Ukraine remains tense Sunday, as Russian forces have tightened their grip over Crimea, a week ahead of a vote in which the region will decide whether it wants to secede.

Talk about what's next dominated the Sunday show conversation. Here's a roundup of the most important comments:

Deputy National Security Adviser Tony Blinken on secession: "If there is a referendum and it votes to move Crimea out of Ukraine and to Russia, we won't recognize it and most of the world won't either." (NBC's "Meet The Press")

On pressuring Russia: "With regard to Russia, in coordination with our allies, we've imposed significant sanctions on Russia, and that's already exerting a cost. We've seen Russian markets go down substantially, the ruble go down, and investors sitting on the fence." (CNN's "State of the Union")

On reports that Russia could move to curb nuclear weapons inspections: "The Russians haven't said anything to us about that directly. We haven't seen any change in their practices. Obviously that would be serious development. Inspections are an important part of arms controls agreements." (NBC's "Meet The Press")

Former defense secretary Robert Gates, predicting: "I do not believe that Crimea will slip out of Russia's hands." ("Fox News Sunday")

Former vice president Dick Cheney on military options: "There are military options that don't involve putting troops on the ground in Crimea. We could go back and reinstate the ballistic missile defense program that was taken out. It was originally going to go in Poland, Czech Republic, Obama took it out to appease Putin. We could do training exercises in Poland, joint exercises. We can offer military assistance in terms of equipment, training and so forth to the Ukrainians themselves." (CBS's "Face The Nation")

Sen. Rand Paul (R-Ky.) on a possible backfire: "If they continue to occupy Crimea, if they annex Crimea, Ukraine almost certainly will come completely within the Western orbit. So it will backfire on them because you'll be taking Russian-speaking voters that have been voting for Russian-speaking presidents of Ukraine -- you'll be taking them out of the population." ("Fox News Sunday")

Rep. Paul Ryan (R-Wis.) on sanctions/U.S. strategy: "I do think there are vulnerabilities within Russia that he has politically that can be exploited. I think we should consider targeting some of the oligarchs around him that are his enablers and he is their enablers." (CBS's "Face The Nation")

Sen. Ted Cruz (R-Tex.) on perceptions of Obama: "A critical reason for Putin's aggression has been President Obama's weakness -- that Putin fears no retribution." (ABCs' "This Week With George Stephanopoulos")

Rep. Joaquin Castro (D-Tex.) on GOP criticism of Obama: "You saw from the very beginning how this was all about politics. Right away, the Republicans jumped on the president, when this should have been a moment that the country was really rallying around the United States and coming together. And that was very strange to see. And I don't think we've seen something like it in the past." (ABCs' "This Week With George Stephanopoulos")

Former Obama national security adviser Jim Jones, on what could cause this to get out of control: "I think precipitous moves that preclude people from being able to step back from it and get to the point where you get boxed in. I think this is a point right now where Mr. Putin has to understand that if he doesn't figure a way to get out of this, that the long-term consequences for him and for Russia could have serious consequences in terms of the economic relationships and the isolation of Russia with regard to Europe." (CBS's "Face The Nation")