Washington, May 9 (RHC)-- U.S. Republican Senator John McCain says GOP presidential candidate Donald Trump should apologize to the prisoners of war (POWs) and other people he has offended during the course of his tumultuous campaign.

The U.S. senator from the state of Arizona told CNN on Sunday that Trump could be a capable president, but first he needs to "heal many of the wounds" he has opened.

Donald Trump, whose campaign has been marked by incendiary remarks, drew heavy criticism last year for mocking McCain's military service, saying: "I like people who weren't captured."

Trump, who became the presumptive GOP nominee after his rivals dropped out this week, has engaged in numerous verbal feuds throughout his campaign, often taking the fight to a personal level.  He sparked outrage last year when he promoted Islamophobia in the US by calling on law enforcement agencies to maintain a database of Muslim Americans and ban them from entering the country.

The real estate mogul also enraged Mexicans by proposing to build wall on the border with the southern neighbor while announcing plans to deport all illegal immigrants back to their countries.

He also has a long history of waging personal attacks against other candidates, Republican and Democratic alike.  And journalists have been frequent targets of Trump’s relentless attacks.