Security at the TCS New York City Marathon on Sunday will be high again, and Mayor Bill de Blasio said the city is confident that the 44th annual event will go off without a hitch.

Four thousand officers will be on patrol, four aircrafts will watch the streets from above and runners will be prohibited from bringing backpacks to the welcoming tent, according to NYPD Commissioner Bill Bratton.

Even though the bombings at the Boston Marathon took place more than 18 months ago and there are no known threats aimed at the race, Bratton said the city will keep the security measures it enacted during last year's event in place.

"We are very prepared. We are very focused," Bratton said at a news conference Thursday at the Jacob Javits Center.

De Blasio joked that he could only run 5 miles and said the marathon brings together residents from all five boroughs.

"It's become synonymous with the spirit of the city," he said at the marathon's kick-off news conference Thursday.

De Blasio also reiterated that the Ebola scare shouldn't put off people from hitting the streets as either participants or spectators. He reiterated that it's very difficult to catch the virus and the city is ready if anything serious happens.

"This year, the best professionals in health and safety have added their input to make sure things will go smoothly," he said.

About 50,000 runners from all over the world will be at the starting line at the Verrazano-Narrows Bridge Sunday morning, according to Mary Wittenberg, president of the New York Road Runners.

Aside from taking in the sights of the city on foot, the runners will get an extra boost from the millions of spectators cheering them on.

"The crowds are what define the race," Wittenberg said.

Many of this year's marathon runners agreed.

Therese Smith, 45, and her husband Ross, 50, came from Sydney to scratch New York off their marathon bucket list.

Therese, who has run 13 races, said they couldn't compare to the Big Apple, which is one of the biggest marathons in the world.

"This is what you aspire to do," she said after she and her husband picked up their bibs at the Javits Center. "It's just phenomenal that you shut down the streets for a race."

Overall, the organizers and runners said they are ready to tackle the urban jungle.

"This is one of the greatest events in the world, one of the biggest events in the world and to have 50,000 running is an amazing journey," said 2014 Boston marathon winner Meb Keflezighi, who aims to take the top prize in the five boroughs on Sunday.