Hundreds, if not thousands, of mourners are expected to pay their respects to fallen NYPD Officer Jonathan Diller at his Saturday funeral.

The procession is scheduled for 10:30 a.m. at St. Rose of Lima Roman Catholic Church, in Massapequa, the same Nassau County hamlet where Diller's two-day wake is being held.

He will be buried at St. Charles Cemetery in Farmingdale immediately after the service.

Thousands of police officers and NYPD supporters are expected to send off Diller in traditional fashion alongside numerous elected officials.

The Sergeants Benevolent Association warned anti-cop politicians to keep their distance from the funeral, with president Vincent Vallelong telling The Post Wednesday that they "should stay home and not pretend they are grieving."

Gov. Kathy Hochul will attend the second day of services for fallen NYPD Officer Jonathan Diller on Friday.

The governor announced plans to visit the 1:45 p.m. viewing at the Massapequa Funeral Home at 4980 Merrick Road.

She will join several other elected officials who have paid their respects to the slain officer, including New York City Mayor Eric Adams and former President Donald Trump.

Ahead of Thursday's funeral, Hochul ordered flags on all state buildings to be flown at half-staff.

“New Yorkers are in mourning over the loss of Officer Jonathan Diller, a heroic young man who dedicated his life to public safety and serving the people,” Hochul said. 

A special operations cop said he only knew Diller in passing, but that his loss feels like that of a family member.

"I've been a police officer in New York for 11 years now," Nick, who works at the Strategic Response Group (SRG 3) in Brooklyn, told The Post.

"I've been to too many of these unfortunately, but when it's one of us, when it's a police officer, we all show up, rain or shine.

"That's our brother in there.

"It's like losing a family member. Whether you knew him or not. It hits us all."

A grieving family friend of Jonathan Diller remembered the slain NYPD officer as a "good all-round guy who came from a really good family."

Deanna Vollmer, of Hoboken, grew up with Diller in Franklin Square, Long Island, where they attended John Street School, an elementary school, together.

"I knew Officer Diller, I knew his mother, his brother and sister and his cousins," Vollmer said.

"As kids we grew up going to Montauk, we all just had a great time together.

Asked how she reacted when she heard the news of Diller's death, Vollmer said: "I was just at a loss for words. "It's never something you want to hear but it hits different when it's someone you know."

Vollmer was one of thousands to brave the driving rain at the back of a 200-yard line for a chance to pay their respects at the viewing.

"It's the right thing to do to pay respects to the family," she said. "It's hard to process."

Former President Donald Trump said the senseless death of NYPD cop Jonathan Diller must not be in vain, he told The Post in an exclusive interview after leaving the hero cop's wake on Long Island.

"In life, some things just capture a moment and this captured a moment," Trump said. "This particular great officer, top of his class — he captured a moment.

"The perfect family has been so tragically altered, forever altered," the former commander in chief said.

"I was telling Stephanie, the wife, who's incredible -- a 1-year-old baby who doesn't know that his life has been greatly affected by this. I said something has to come out of it, and the only thing that you could really think that could come out of it is we get stronger and tougher so this doesn't keep happening."

Trump, who spoke to The Post from his private plane on the tarmac at Long Island MacArthur Airport, also railed against New York City's "How Many Stops Act."

"It's not going to have any impact other than it's going to give criminals more time to roam," he said. "And they have to be able to protect our police."

Trump shook the hand of NYPD Commissioner Edward Caban on the way into the Massapequa Funeral Home. 

Diller’s colleagues from the specialized community response team stood outside the funeral home when Trump exited the building.

After the former president left, hundreds of cops were waiting in line to pay their respects at Diller's casket. There are some tents but most cops are just standing in the rain, waiting patiently.

The flag pole outside the funeral home is flying the US flag and two thin blue line flags. There’s a rolling billboard stationed outside showing a slideshow of Diller and his family with a message from the Police Benevolent Association: “In loving memory of our brother P.O. Jonathan E. Diller.” 

Nassau County Executive Bruce Blakeman said Trump's visit was "very comforting" for the Diller family.

The Republican, who held an umbrella up for Trump as he spoke in the rain, addressed the media following the ex-president's remarks.

"People were very, very, very blessed to have someone like President Trump, who cared so much, spent a lot of time with the family," Blakeman said.

"Brian, we are going to help raise, because he's only one years old. He's going to grow up without a dad, but he's going to have thousands of dads that will look after him," he continued, while gesturing around at the assembled NYPD officers.

Former President Donald Trump spoke to the crowd of mourners about “toughening up” law and order after visiting Diller's wake. 

Nassau County cops stood behind Trump outside the funeral home as he delivered his remarks in the rain.

“What happened is such a sad event,” Trump told reporters. “It’s happening all too often and we’re just not going to let it happen.

“Twenty-one times arrested, this thug," he said, referring to Diller's suspected killer, ex-con Guy Rivera.

“The person in the car with him was arrested many times and they don’t learn because they don’t respect," the former president added.

“The Diller family will never be the same. We have to stop it. We have to get back to law and order.”

“We have to do a lot of things differently because this is not working. This is happening too often,” Trump said. 

“This is such a sad occasion. The only thing we can say is maybe something’s going to be learned. We’ve gotta toughen it up and strengthen it up. 

“Things like this shouldn’t take place and take place so often. We’ve gotta toughen it. We’ve gotta have law and order. These things can’t happen. We need law and order.”

After Trump spoke, the crowd yelled, “Thank you, President Trump.”

Former President Donald Trump addressed the public Thursday after paying his respects to the family of fallen NYPD Officer Jonathan Diller.

Diller, 31, was gunned down during a traffic stop in Queens on Monday.

Donald Trump arrived at the Massapequa Funeral Home Thursday afternoon to pay respects to fallen NYPD officer Jonathan Diller, who was killed during a traffic stop in Queens earlier this week.

Clad in a blue suit and red tie, the presumptive Republican presidential shook hands with mourners before walking into the suburban funeral parlor, before NYPD cops in dressed in formal uniforms shut the door behind him.