A new congressional probe into the State Department’s handling of the 2012 attack in Benghazi, Libya, and escalating unrest in Ukraine will likely dominate Sunday talk show news.

Pro-Russian separatists in eastern Ukraine insist that a controversial referendum set for Sunday declaring sovereignty over the region will happen. The referendum will likely take place in the Donetsk and Luhansk regions of eastern Ukraine, where armed groups have been involved in deadly clashes with Ukrainian security forces recently. Several Western powers have condemned the planned vote as illegitimate as well as the interim government in Kiev. 

Meanwhile, House Republicans are moving forward with a select committee to investigate the Benghazi attack that left four Americans dead, including U.S. Ambassador Christopher Stevens.

The abduction of more than 200 Nigerian schoolgirls this week by Islamist terrorist group Boko Haram will also be a topic of discussion.

Here's the lineup:

ABC's "This Week:" Defense Secretary Chuck HagelCharles (Chuck) Timothy HagelIntel chief: Federal debt poses 'dire threat' to national security Hagel: Trump is 'an embarrassment' Tax cut complete, hawks push for military increase MORE, Sen. Marco RubioMarco Antonio RubioColbert: Students taking action on gun violence 'give me hope' Lawmakers feel pressure on guns Florida lawmaker's aide fired after claiming shooting survivors were 'actors' MORE, (R-Fla.), Rep. Adam Kinzinger, (R-Ill.)

NBC's "Meet the Press:" Pre-empted by coverage of Premier League soccer.

CBS' "Face the Nation:" Former Defense Secretary Robert Gates, House Intelligence Chairman Mike Rogers, (R-Mich.), Sen. Elizabeth WarrenElizabeth Ann WarrenTrump's SEC may negate investors' ability to fight securities fraud Schatz's ignorance of our Anglo-American legal heritage illustrates problem with government Dems ponder gender politics of 2020 nominee MORE, (D-Mass.)

CNN's "State of the Union:" Rep. Michele BachmannMichele Marie BachmannBachmann won't run for Franken's Senate seat because she did not hear a 'call from God' Billboard from ‘God’ tells Michele Bachmann not to run for Senate Pawlenty opts out of Senate run in Minnesota MORE, (R-Minn.), Rep. Debbie Wasserman Schultz, (D-Fla.), former senator Rick Santorum, (R-Penn.)

"Fox News Sunday:" Rep. Trey GowdyHarold (Trey) Watson GowdyOvernight Energy: Dems ask Pruitt to justify first-class travel | Obama EPA chief says reg rollback won't stand | Ex-adviser expects Trump to eventually rejoin Paris accord Overnight Regulation: Trump to take steps to ban bump stocks | Trump eases rules on insurance sold outside of ObamaCare | FCC to officially rescind net neutrality Thursday | Obama EPA chief: Reg rollback won't stand GOP lawmakers: Obama admin ‘hastily’ wrote lead ammunition ban MORE, (R-S.C.), Rep. Xavier BecerraXavier BecerraCourt rules Energy Dept. must implement Obama efficiency rules California secession supporters file new initiative Overnight Finance: Breaking down Trump's budget | White House finally releases infrastructure plan | Why it faces a tough road ahead | GOP, Dems feud over tax-cut aftermath | Markets rebound MORE, (D-Calif.)

NPR’s “Weekend Edition Sunday:" Maria Korsnick, the first female chief nuclear officer in the U.S.; NPR’s Jeff Brady on the Keystone Pipeline project.