Two big stories dealing with foreign affairs are set to consume the Sunday political news shows: the vote in Crimea to secede from Ukraine and the mystery of the missing Malaysian jetliner carrying 239 passengers.

What to do in Ukraine?

Sen. Robert Menendez, R-N.J., and Sen. Bob Corker, R-Tenn., top officials of the Senate Foreign Relations Committee, will appear on Fox News Sunday to discuss what will happen for Ukraine and the U.S.-Russia relationship if Crimeans vote to join Russia.

Another House heavyweight, Intelligence Committee chairman Rep. Mike Rogers, R-Mich., will join CBS’ Face the Nation for discussion of the same topic, as well as Tom Donilon, President Barack Obama’s former national security adviser.

Two senators coming back from Ukraine, Sens. Dick Durbin, D-Ill., and Jeff Flake, R-Ariz., will be on NBC’s Meet the Press. CNN's State of the Union will have Sen. John McCain, R-Ariz., who also speaks after spending time in Ukraine.

Malaysia Airlines Flight 370

The news on Malaysia Airlines Flight 370 is ever-changing, with information suggesting the 239-passenger plane may have traveled for several hours after losing contact and Chinese scientists on Friday noting a "seismic event" on the seafloor that could mean the plane crashed into the water between Vietnam and Malaysia.

Fox brings in Rep. Michael McCaul, R-Texas, chairman of the House Homeland Security Committee, and Peter Goelz, a former National Transportation Safety Board member, to discuss the mystery of the missing Malaysian plane.

CBS has Capt. Sully Sullenberger, former NTSB chairman Mark Rosenker and CBS News correspondent Bob Orr.

One-on-ones

ABC’s This Week touts an exclusive interview with billionaire Bill Gates. The subject? The controversy over Common Core education standards.

Meet the Press host David Gregory will question White House senior adviser Dan Pfeiffer about Obama's next moves on the Ukrainian crisis, the administration's position on Senate allegations about CIA spying, and the Democratic Party's chances in the 2014 midterms.

Republican National Committee chairman Reince Priebus joins CNN to talk about the GOP's "autopsy" of its 2012 presidential election loss.

The roundtables

Fox News Sunday: Columnist and Fox contributor George Will, PBS Newshour co-anchor and managing editor Judy Woodruff, conservative political commentator Karl Rove, and Fox News political analyst Juan Williams.

ABC's This Week: ABC News political analyst Matthew Dowd, Georgetown University professor Michael Eric Dyson, Weekly Standard editor and ABC News contributor William Kristol, editor and publisher of The Nation Katrina vanden Heuvel, and Fox News anchor Greta Van Susteren.

NBC's Meet the Press: Ralston Reports' Jon Ralston, former Obama White House press secretary Robert Gibbs, New York Times Washington bureau chief and political editor Carolyn Ryan, and Heritage Foundation strategic initiatives manager Israel Ortega.

CBS' Face the Nation: Time magazine writer and editor Bobby Ghosh, Washington Post diplomatic correspondent Anne Rumsey Gearan, columnist Michael Gerson, and CBS News correspondent Margaret Brennan.

CNN's State of the Union: New York Times columnist Charles Blow, Republican strategist Ana Navarro, and CNN senior political analyst Ronald Brownstein.