US officials disclosed that the deployment of thousands of National Guard soldiers to contain massive demonstrations on Washington's streets, endorsed by President Donald Trump and condemned by the mayor of the city, cost the US government around $2.6 million - per day - during its peak, Reuters reported. 

A Reuters review of the National Guard data found that the deployments cost around $14.5 million over a seven-day period starting June 1.

At its peak, some 1,200 troops from the National Guard and nearly 4,000 from other states were deployed to the country's capital to reinforce local police during protests that broke out over the killing of George Floyd, a 46-year-old black man who died in police custody in Minneapolis after he was pinned to the ground by a white police officer's knee for almost nine minutes.

Approximately $18.2 million of the total cost of the operation was earmarked for payment and allowance for the National Guard and nearly $3 million went to operations, logistics and management, including lodging and transportation.

The approximate cumulative count does not include aircraft costs that were used to move personnel from supporting states to the capital. It also excludes other separate law enforcement groups that were sent to DC to tackle the demonstrations.

William Barr, the US Attorney General confirmed reports that all the major law enforcement units of the Justice Department took part in the operation, "including the FBI, DEA, ATF, Bureau of Prisons, and US Marshals Service," Gursimran Hans of Express, reported.

The amount was not even the most it cost to send National Guard troopers to Washington. In California, it cost the federal government around $25 million, while in Minnesota - where the protests started after Floyd's death - it cost the government $12.7 million.

Senator Chris Van Hollen (D) described the President's use of the states' National Guard soldiers against the demonstrations as offense to the US Constitution and an example of Republicans compromising the capital's right to self-governance.

In a statement to Reuters, as reported by Idrees Ali and Makini Brice, Van Hollen said the "administration's use of taxpayer dollars to send National Guard troops ... and their refusal to provide details on these costs - is unacceptable."

Meanwhile, an aide said that the Maryland senator will be asking the Department of Defense in the coming days for a formal answer on how much the federal government spent on the deployment of the National Guard.