Presumptive Republican nominee Donald Trump tore into the AFL-CIO's endorsement of Hillary Clinton, which the labor group handed down earlier Thursday after declining to wade into her Democratic primary race against Sen. Bernie Sanders.

In a statement, Trump argued that the labor union "no longer represents American workers," before predicting that the majority of the group's members will end up backing Trump in November over the former secretary of state.

"Sadly with this endorsement of Hillary Clinton ... the leadership of the AFL-CIO has made clear that it no longer represents American workers. Instead they have become part of the rigged system in Washington, D.C., that benefits only the insiders," Trump said in the statement. "I believe their members will be voting for me in much larger numbers than for her."

Trump went on to hit Clinton over a myriad of issues, including immigration, energy, taxes and trade. Notably, Trump invoked Sanders in his attacks against Clinton, particularly for her support of the North American Free Trade Agreement and other pacts.

"Bernie Sanders is also 100 percent correct when he says that Hillary Clinton 'vote[d] for virtually every trade agreement that has cost the workers of this country millions of jobs,'" Trump said. "Hillary supported NAFTA and she supported the trade deal with China, Vietnam, South Korea — and if elected will implement the TPP she loves so much — guaranteed."

"Hillary Clinton is the enemy of working people and is the best friend Wall Street ever had," Trump said. "I will fight harder for American workers than anyone ever has, and I will fight for their right to elect leaders who will do the same. I will be a president for ALL Americans."

With the endorsement, Clinton begins the process of bringing organized labor to her side heading into November. Richard Trumka, who heads the union, called Clinton a "proven leader who shares our values" despite holding out their support until after the primary contest.