The comments were a remarkable acceleration of tensions between a president aggrieved at his lack of significant legislative accomplishments and a lawmaker in charge of shepherding his agenda through a Republican-led Congress.
They also signaled a conspicuous desire from Mr. Trump, who often campaigned as a renegade outsider with few meaningful allegiances to either party, to position himself once more as a crusader against Washington gridlock — even though he and his allies are now at the controls, grinding the gears.
Some Trump advisers see value in creating distance from a Congress with dismal poll numbers, despite the Republican majorities.
Yet while the confrontation seemed destined to hearten some conservative news media figures, like Sean Hannity, who have flamed Mr. McConnell since the failed health care vote, it is unlikely to improve the faltering shotgun marriage between Mr. Trump and congressional Republicans.
“It’s a team problem; the president has to own a piece of this,” said Newt Gingrich, the former House speaker and an informal adviser to Mr. Trump. “I may not be clever enough to understand this, but I don’t see how a Republican president deepening his fight with the Republican majority leader gets him very far.”
Though Mr. Trump has far outstripped Mr. McConnell in public fury, it was the senator who initiated the flare-up this week. Speaking on Monday at a Rotary Club event in Kentucky, he said Mr. Trump had harbored “excessive expectations” about the pace of progress at the Capitol.
The remarks, though hardly scorching, registered as a pointed message from the laconic Senate leader, who has strained all year to wrangle his narrow majority. Mr. McConnell has gotten little help from an often disengaged and policy-averse president whose habit of setting arbitrary (and often shifting) deadlines has frustrated senators for months.
On Wednesday, Mr. Trump grew animated in a phone call with Mr. McConnell, expressing disappointment in the “excessive expectations” message and the repeal stumble.
On Thursday, Mr. McConnell’s team showed little appetite for a protracted feud.
“As we’ve said, the leader has repeatedly spoken about the path forward on repealing and replacing Obamacare — on the Senate floor, at media availabilities and in Kentucky,” said Antonia Ferrier, Mr. McConnell’s spokeswoman, in an email, using language nearly identical to a statement issued the day before. “But if he has any new statements today, I’ll be sure to send them along.”
For Mr. McConnell — who helped engineer perhaps Mr. Trump’s most meaningful feat to date, the elevation of Justice Neil M. Gorsuch to the Supreme Court — the episode follows a health care defeat that has tested the unity of his conference.
After a seven-year push to unravel President Barack Obama’s signature domestic achievement, Republican senators saw three of their own doom the effort last month in a dramatic early-morning vote: Susan Collins of Maine, Lisa Murkowski of Alaska and John McCain of Arizona.
Other Republicans, returning to their home states this month with little to boast about, have seethed at the outcome, exposing persistent divisions and, occasionally, peculiar justifications. Senator Ron Johnson of Wisconsin suggested this week that Mr. McCain’s choice may have been affected by his brain tumor.
Still, there is little doubt that Mr. McConnell retains a firm hold on his power.
Several Republican senators emphasized their support on Thursday, while taking care not to scold Mr. Trump explicitly.
“I have every confidence in Leader McConnell, as does the rest of the conference,” said Senator John Barrasso, Republican of Wyoming and a member of Mr. McConnell’s leadership team. “His leadership remains indispensable for unity and legislative success this fall.”
In a statement posted on Twitter, Senator Orrin G. Hatch of Utah, the longest-serving Republican in the chamber, said Mr. McConnell “has been the best leader we’ve had in my time in the Senate, through very tough challenges.”
Others, like Senator Richard M. Burr of North Carolina and Senator Jeff Flake of Arizona, also reiterated their faith in Mr. McConnell.
Even some Trump allies have questioned the wisdom of antagonizing his ostensible partners in conservative policy making.
“All you do is get a lot more senators irritated,” Mr. Gingrich said, arguing that Mr. McConnell “probably does about as good a job as he can” under the circumstances. “I don’t see an endgame to this.”
Mr. Trump himself has occasionally sounded notes of harmony this week. With a coming special election primary in Alabama, the president endorsed Mr. McConnell’s preferred choice, Senator Luther Strange, in a Twitter message on Tuesday evening.
But as his frustrations boiled from his New Jersey golf club during his 17-day working vacation, the president increasingly trained his fire on Mr. McConnell.
“Can you believe that Mitch McConnell, who has screamed Repeal & Replace for 7 years, couldn’t get it done,” he tweeted on Thursday morning. “Must Repeal & Replace ObamaCare!”
Questioned by reporters on Thursday about their relationship, Mr. Trump repeatedly wondered aloud why Republicans in Congress had not done their part.
“All I hear is ‘repeal and replace,’” Mr. Trump said of Republicans before he took office. “And then I get there, and I said, ‘Where’s the bill? I want to sign it,’ first day. And they don’t have it.”
Mr. Trump added that it was “a disgrace” that the repeal measure failed by a single vote. “Frankly, it shouldn’t have happened,” he said. “That, I can tell you — it shouldn’t have happened.”
McConnell allies have argued that the White House was a less-than-helpful resource in persuading two of the three senators who opposed the bill. As Ms. Murkowski held out, Mr. Trump directed his interior secretary, Ryan Zinke, to remind the senator of issues affecting her state that are controlled by the Interior Department, according to people familiar with the conversation.
And Mr. McCain has long been deeply skeptical of Mr. Trump, who suggested during the campaign that the senator was not a war hero because he was captured in combat.
Holding forth on Thursday, Mr. Trump did allow for the possibility that he could change his mind about Mr. McConnell, saying he would be “very happy with him” if legislation starts churning.
The president was asked if he had considered recruiting Mr. McConnell’s wife, Elaine Chao, the transportation secretary, to help bridge the divide.
He could not resist a contrast.
“She’s doing a very, very good job,” Mr. Trump said. “I’m very disappointed in Mitch.”