Gov. Andrew Cuomo agreed on Monday with a front-page Post editorial demanding Mayor Bill de Blasio’s ouster for being an absentee mayor — but said he wasn’t ready to “exercise my legal authority” to make it happen.

“I understand their point,” Cuomo, who is empowered by the City Charter to remove the mayor, told WNYC radio.

Cuomo mounted a third consecutive day of attacks on his longtime political rival for campaigning in Iowa when a large swath of Manhattan was blacked out Saturday night.

De Blasio did not get back to the city until Sunday afternoon, after first driving to Chicago and making a Sunday-morning appearance on CNN.

“I believe that a chief executive is there and should show up,” Cuomo said. “I showed up at the Con Ed situation. I show up when something happens in Buffalo. I think it is important to be there, to be on the ground, to manage the situation.”

The governor reiterated that de Blasio’s out-of-town travels became an issue when Hizzoner launched his long-shot White House bid in May after two months of testing the waters in early-voting states.

When WNYC host Brian Lehrer spoke up for de Blasio — saying the mayor “headed for home” from Waterloo, Iowa, upon learning about Saturday night’s power outage — Cuomo rejected the defense.

“I think The Post’s point is you can’t do both,” he said.

“You can’t be mayor, and you can’t run for president. I think that is what The Post was saying.”

And while Cuomo punted when asked if he felt that “you can’t have one important job and run for another at the same time,” he noted the different obligations placed on various elected officials.

“I think it is one thing for a legislator. I do believe it gets more difficult for a chief executive,” he said.

He cited another 2020 Democratic hopeful — Pete Buttigieg, mayor of South Bend, Ind. — as a comparison.

“I think Mayor Pete has run into the issue,” Cuomo said. “Because … there are more day-to-day operational issues for a chief executive where you are needed on set.”

Cuomo’s remarks came during a round of TV and radio interviews in which he criticized de Blasio’s absence during the five-hour blackout.

But while acknowledging that state and city law allow a governor to suspend a mayor for 30 days and file charges to remove them from office, Cuomo said he wouldn’t do so.

“At least one tabloid this morning is calling for you as the chief executive of New York state, as in the city is a creature of the state — an old political-science axiom — to fire him,” WAMC host Alan Chartock noted to Cuomo.

Cuomo replied, “It’s not an old political axiom; it’s the law, by the way,” affirming his authority to remove the mayor for cause.

But, he added, “I am not going to exercise my legal authority to move against [de Blasio].

On Fox 5’s “Good Day New York,” co-host Rosanna Scotto urged Cuomo to “think about that little clause” after co-host Sukanya Krishnan said the mayor “ghosted New York City” and “a lot of people are saying that you should be the one … governing New York City.”

On WAMC, Cuomo said he learned how to handle emergencies while serving as secretary of Housing and Urban Development under President Bill Clinton.

“Lesson one in emergency management is show up. Show up. Why? Because there’s no substitute for firsthand information and firsthand knowledge,” he said.

“Secondly: people. You’re trying to keep the public calm and instill confidence. People want to see their leader on site, in charge, in control, and it makes people feel more confident, which is very important because in these situations … chaos is the problem.”

De Blasio tried to spin his blackout absence as evidence of his presidential qualifications.

“When you’re chief executive, it doesn’t matter where you are,” he said on MSNBC’s “Morning Joe.” “You’re in charge of your team and making sure people are executing the plan.”

On Sunday, de Blasio claimed he “started moving” immediately upon learning of the blackout — although he squeezed in an appearance from Chicago on CNN’s “State of the Union” before arriving in New York at around 12:30 p.m.

City Hall didn’t respond to a request for comment.