(CNN) Sen. Jeff Flake is warning that he may block votes on the nominations of all of President Donald Trump's pending appellate court nominees unless he gets favorable action on two issues unrelated to the judiciary.

According to one source, Flake wants to spur discussions on travel restrictions to Cuba as well as issues related to tariffs.

"We're discussing it," the Arizona Republican said in a brief interview with CNN as he came out of an immigration negotiation.

Flake sits on the Judiciary Committee, where Republicans have a slim 11-10 advantage over Democrats. If he does not relent, he could bring the work of the powerful committee to a halt as it applies to appellate court nominees, who are often voted out on party lines.

Confirming these influential circuit court nominees has been a top priority and bragging point for Senate Majority Leader Mitch McConnell and Trump.

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