Trump loyalist Matt Schlapp dismissed CNN reporter Jim Acosta's report that President Trump was "lying" when he said the late Sen. John McCain promised to support an Affordable Care Act repeal, which he then voted against and helped defeat.

Acosta, CNN's chief White House correspondent, tweeted Tuesday that a former McCain aide told him the senator never reneged on the healthcare vote.

"A former McCain aide says Trump was lying when he claimed today the senator had misled the WH and said he was going to support 'repeal and replace' effort before changing his mind. 'Nope. Never happened,' the former aide said. 'You’re surprised Trump lied?' the ex-aide added," Acosta said.

Schlapp, the chairman of the American Conservative Union and husband to White House director of strategic communications Mercedes Schlapp, shot back.

"This is not accurate @Acosta," Schlapp said. "McCain met w me in my office and pledged to support every version of repeal and replace and said he would lead the charge. Everyone was worried he would flip flop when it mattered and well he did on the flight to dc."

[Opinion: Trump should stop attacking and lying about McCain]

This is not accurate @Acosta. McCain met w me in my office and pledged to support every version of repeal and replace and said he would lead the charge. Everyone was worried he would flip flop when it mattered and well he did on the flight to dc. https://t.co/C4aGFc2An7 — Matt Schlapp (@mschlapp) March 20, 2019

Acosta replied: "Hi Matt.. Trump said earlier today that McCain 'told us, hours before, that he was going to repeal and replace.' A former aide for McCain said that story is false."

In response, Schlapp said he was closely following the whip count for the vote in the summer of 2017 and argued that everyone, including the president, were told McCain was guaranteed to vote in favor of the repeal-and-replace plan.

"Jim I was tracking the Senator up until the vote. Everyone was told he was 'solid' on his vote against Obamacare but all of us knew Sen McCain was unpredictable. None of us including the President are lying about this," the vocal Trump supporter said, adding in a follow-up tweet that even Sen. Lindsey Graham, R-S.C., a close friend to McCain was surprised.

Jim I was tracking the Senator up until the vote. Everyone was told he was “solid” on his vote against Obamacare but all of us knew Sen McCain was unpredictable. None of us including the President are lying about this. https://t.co/OSUQC9H9vl — Matt Schlapp (@mschlapp) March 20, 2019

Trump took shots at McCain, R-Ariz., during an Oval Office meeting with Brazilian President Jair Bolsonaro.

“I'm very unhappy that he didn't repeal and replace Obamacare, as you know. He campaigned on repealing and replacing Obamacare for years and then they got to a vote and he said thumbs down,” Trump said.

Trump said that had Congress passed legislation repealing and replacing the 2010 healthcare law, the country would’ve saved $1 trillion and had “great healthcare.” The president also suggested McCain promised to support the GOP’s efforts to dismantle Obamacare but went back on his word.

“So he campaigned, he told us hours before that he was going to repeal and replace. Then, for some reason — I think I understand the reason — he ended up going thumbs up,” he said, apparently meaning to say "thumbs down."

Trump called McCain’s deciding vote against a “skinny repeal” of Obamacare “disgraceful.”

Melissa Quinn contributed to this report.