WASHINGTON - The father of U.S. Army Captain Humayun Khan has called on Republican leaders to repudiate Republican presidential nominee Donald Trump for comments seen by many as attempts to degrade the sacrifices of his late son and those of Muslim Americans in general.

Speaking Sunday on national television, Khizr Khan described Trump as " totally unfit for the leadership of this beautiful country."  He also described the party nominee as possessing a "black soul" and called on Republicans Mitch McConnell and Paul Ryan to speak out against their candidate.

The senior Khan and his wife, Ghazala, first came to prominence at last week's Democratic nominating convention when the couple memorialized their son, who was killed by a suicide bomber in Iraq, and then strongly endorsed Democratic nominee Hillary Clinton.

Khan, a Pakistani immigrant, said in an emotional speech that his family would never have been allowed to immigrate to the United States under Trump's proposed immigration policies.

Lacks empathy

Khan added in a television interview Sunday that Trump lacked empathy and had "sacrificed nothing and no one" during his life, escalating a war of words on social media that soon reached a fevered pitch as Senate Majority leader Mcconnell and House Speaker Ryan sought to distance themselves from the controversy.

Republican presidential candidate Donald Trump spe
Republican presidential candidate Donald Trump speaks during a campaign rally at the Wings Over the Rockies Air & Space Museum, in Denver, Friday, July 29, 2016.

In statements, the congressional leaders condemned any criticism of Muslim Americans who serve their country.  They also rejected Trump proposals for a ban on Muslims seeking entry to U.S. territories, but did so without mentioning Trump by name.

Earlier, in an interview aired on ABC News, Trump replied to the criticism saying "I think I've made a lot of sacrifices. I work very, very hard," creating "thousands and thousands of jobs. I think those are sacrifices, I think when I can employ thousands and thousands of people, take care of their education, take care of so many things." 

The Republican contender also questioned why Ghazala Khan stood by her husband while he spoke at the convention and said nothing.  "Maybe she wasn't allowed to have anything to say," Trump said on Twitter.

Ghazala Khan reacts

For her part, Ghazala Khan, writing in The Washington Post, said "walking onto the convention stage, with a huge picture of my son behind me, I could hardly control myself. What mother could?" She said her husband asked her if she wanted to speak, "but I told him I could not."

"Donald Trump said he made a lot of sacrifices," she concluded. "He doesn't know what the word means."

Trump's opponent in November polls, former U.S. Secretary of State Hillary Clinton, again accused Trump of trying to inflame divisions in American society.  Speaking in Ohio, she said her opponent had a "total misunderstanding" of American values.

Democratic presidential candidate Hillary Clinton
Democratic presidential candidate Hillary Clinton speaks on her campaign bus after visiting Imani Temple Ministries in Cleveland, 2016.

Separately, leading U.S. veteran group organizer Paul Rieckoff called Trump's move to equate the "sacrifice" of creating jobs with those of people who had lost a son in combat "insulting, foolish and ignorant."

By midday Sunday, Trump, the real estate tycoon seeking public office for the first time,  sought to reframe his comments.

"Captain Khan, killed 12 years ago, was a hero, but this is about Radical Islamic Terror and the weakness of our 'leaders' to eradicate it," Trump said in one tweet.

In another comment, Trump said, "I was viciously attacked by Mr. Khan at the Democratic convention. Am I not allowed to respond? Hillary voted for the Iraq war, not me!"

As a U.S. senator, Clinton voted along with other lawmakers in approving the 2003 U.S. invasion of Iraq that toppled Iraqi dictator Saddam Hussein.  The invasion led to an eight-year war that many Americans came to oppose, including Clinton. The premise for the U.S. invasion, that Saddam Hussein had amassed weapons of mass destruction, turned out to be unfounded.

Members of the audience stand in front of a large
Members of the audience stand in front of a large American flag as Democratic presidential candidate Hillary Clinton, accompanied by Democratic vice presidential candidate, Sen. Tim Kaine, D-Va., speaks at at rally at Fort Hayes Metropolitan Education Center in Columbus, Ohio, July 31, 2016.

Candidates head to battleground states

Trump planned to campaign Monday in the industrial states of Ohio and Pennsylvania - key election battleground states where Clinton is also touring.

Speaking at a wire manufacturing plant in Johnstown, Pennsylvania Saturday, Clinton said she was not there to insult her opponent and make "crazy promises," but to tell voters of plans to "make the biggest investment in new, good-paying jobs" since World War II.

Clinton proposed what she calls an infrastructure bank to pay for projects, such as road building and new bridges, instead of having to go to Congress for the money every time.

She said the country cannot go back to what she says were failed economic policies of the past such as tax cuts for the wealthy. She said the rich have to pay their fair share and "support America."

Republican presidential candidate Donald Trump sha
Republican presidential candidate Donald Trump shakes hands during a campaign rally at Wings Over the Rockies Air and Space Museum, Friday, July 29, 2016, in Denver.

Ohio, Pennsylvania

Ohio and Pennsylvania are likely to be key states in the November election.  While most recent polls show Clinton narrowly leading in both states, blue collar voters could swing either state to Clinton or Trump.  

Much of Trump's success this year has come from appealing to working class voters who worry that the U.S. is losing jobs to overseas competitors with cheaper labor.

Trump took to Twitter to say the turnout was "small and unenthusiastic" at Clinton's Johnstown event, and suggested it might be due to the fact that her husband, former President Bill Clinton, supported the North American Free Trade Agreement, a pact with Mexico and Canada that Trump claims sent U.S. jobs to Mexico.