WASHINGTON (Reuters) - In a move to bolster support among veterans, Republican Donald Trump joined a leather-jacket-wearing, motorcycle-riding crowd in Washington on Sunday to honor fighters who served in foreign wars and advocate for those still missing in action. Riders from across the country converged on the National Mall near the Lincoln Memorial for the annual “Rolling Thunder” rally and to listen to the presumptive Republican presidential nominee, who hopes to be commander in chief next year. “We’re going to rebuild our military and we’re going to take care of our veterans,” Trump told the crowd of thousands, many of whom wore leather vests, veterans’ hats and biker insignia. Trump, the billionaire businessman who has promised to build a wall along the U.S. border with Mexico if he becomes president, said illegal immigrants in many cases got better care in the United States than military veterans. “We’re not going to allow that to happen any longer,” he said. Trump, 69, who did not serve in the military, upset veterans last year when he said Senator John McCain of Arizona was not a war hero.  McCain, a Navy fighter pilot who went on to become the 2008 Republican presidential nominee, was imprisoned and tortured after being shot down during the Vietnam War. Trump made no mention of McCain during his remarks on Sunday, and the crowd cheered him enthusiastically, with some waving signs including “Bikers for Trump” and “Make America Great Again.” Supporters cheered when Trump mentioned veterans and booed at the mention of Democratic presidential candidates Hillary Clinton and Bernie Sanders. “I don’t know if he can fix (veterans’ issues), but he’s the only one I think will try,” said Leonard Westberry, 68, of Richmond, Virginia, a U.S. Army veteran who served in Vietnam in 1967. Westberry said he planned to support Trump in the Nov. 8 election. “It’s awesome that Trump is here. ... That’s a good thing,” said Ralph Giannola, 65, who said he had not decided whether to support Trump in November. “I just don’t want to see any rioting. I mean, protests are OK. I don’t want to see anybody get hurt,” he said. There were no protest interruptions during Trump’s nearly 20-minute address on Sunday, a rarity for similar events. “I know one thing, you’re going to all behave yourselves, right?” Trump said to positive affirmations from the crowd. “And I know another thing - there won’t be any paid agitators in this group,” he added to cheers. 