President Donald Trump on Wednesday iterated his previous calls for the death penalty for those who kill police officers.

The Republican made the statement during a speech for the National Peace Officers' Memorial Day service on Capitol Hill on Wednesday. The event honors law enforcement officers who have died in the line of duty.

"The ambushes and attacks on our police must end, and they must end right now,” Trump said. “We believe that criminals who murder police officers should immediately, but with trial, get the death penalty.”

"But quickly. The trial should go fast. It’s got to be fair, but it’s got to go fast," the president added.

This is not the first time the Republican has called for the death penalty for criminals guilty of killing police officers. Trump had made a similar call in one of his 2016 presidential campaigns.

Trump, during his campaign, had said that he will issue an executive order once he gets elected, stating that "anybody killing policemen, policewomen, police officer, anybody killing a police officer, death penalty is going to happen.”

Trump, last year, told law enforcement officers in Florida that "reducing crime begins with respecting law enforcement” and that "criminals who kill our police officers should immediately, with trial, but rapidly as possible, not 15 years later, 20 years later – get the death penalty.”

The Republican till now has not issued a particular policy proposal that addresses the issue. 

According to the National Law Enforcement Officers Memorial Fund, in 2019 so far, at least 18 police officers have been shot and killed in the country in the line of duty. The figure, however, shows a decrease from the numbers last year, when 63 officers were killed in the first five months of the year. In 2018, a total of 160 police officers were killed.