Sen. Bill Cassidy (R-LA) pressed for proof on Sunday that Donald Trump Jr. paid back a Russian oligarch who funded his wedding festivities.

Speaking on CBS News’s Face the Nation, Cassidy was asked about the revelation that Umar Kremlev, president of the International Boxing Association and a close ally of Russian President Vladimir Putin, had given the president’s son hundreds of thousands of dollars to fund his wedding celebration. After President Donald Trump said his son paid it back, Cassidy said that “does make a difference.”