Republican presidential candidate Donald Trump on Saturday called on Bernie Sanders supporters to unite against presumptive presidential Democratic nominee Hillary Clinton.

Trump tweeted: “The Bernie Sanders supporters are furious with the choice of Tim Kaine, who represents the opposite of what Bernie stands for. Philly fight?”

Clinton on Friday announced Virginia Sen. Tim Kaine as her running mate. Kaine, an experienced politician seen as a strong centrist, was widely thought to be Clinton’s safest pick.

But the Trump campaign wasted no time in slamming Kaine on social media.

“Tim Kaine is, and always has been, owned by the banks,” Trump tweeted. “Bernie supporters are outraged, was their last choice. Bernie fought for nothing!”

Trump also name-checked Sanders during his primetime speech on the last day of the Republican National Convention in Cleveland, reaching out to Sanders supporters join the Trump train.

“I have seen firsthand how the system is rigged against our citizens, just like it was rigged against Bernie Sanders. He ever had a chance,” Trump said. “But his supporters will join our movement, because we will fix his biggest issue.”

Despite the shout-out, Sanders tweeted a laundry list of reasons why his supporters should not back Trump.

He added, “Is this guy running for president or dictator?” Sanders tweeted.