Donald Trump has threatened to sue ABC News over its coverage of the chaos engulfing his troubled Reflecting Pool renovation, claiming he wants the network's money sent to the US Treasury.

The president launched the extraordinary swipe on Monday night as workers battled algae, peeling blue coating and alleged vandalism at the Washington D.C. landmark, which Trump had ordered repainted in what he described as 'American flag blue.'

Trump accused ABC of failing to mention what he said were the enormous sums of money spent under Barack Obama and Joe Biden on the 2,000ft long pool while also reviving his long-running feud with the network over its previous $16million payment to settle a defamation lawsuit.

'In describing the Vandalism that took place at the Reflecting Pool in Washington, D.C., ABC FAKE NEWS, one of the worst in the business, even paying me $16,000,000 for past bad and inaccurate reporting, failed to report that their close 'friends,' Dumocrats Obama and Biden, spent over 100 Million Dollars on the Reflecting Pool, and it never worked,' Trump wrote on Truth Social.

He claimed the pool had been 'rarely open due to leaks and 'stench,' and said previous plans would have cost between $300million and $400million before being abandoned.

Trump said his administration had spent approximately $16million on the latest overhaul, while insisting the work had been more extensive than first anticipated.

'I spent approximately 16 Million Dollars, and it came out great, except for the Vandalism, which we are now fixing,' he wrote. 'It was also a much bigger job than originally envisioned, including the outer areas and sidewalks.'

The president then made clear that he was considering legal action against the broadcaster.

'We are preparing lawsuits against ABC for false reporting,' Trump wrote. 'I like their money, which will be given to the US Treasury!'

The threat came after a bruising weekend for the project, which was meant to give one of Washington's most recognizable landmarks a fresh look ahead of the country's 250th anniversary celebrations on July 4.

Trump had ordered contractors to drain the pool and coat its surface in blue, saying the color would better reflect the Washington Monument.

But the makeover quickly ran into visible problems.

Algae bloomed after the pool was refilled, turning sections of the water a murky green. The new blue surface then began to peel, leaving loose strips and patchy areas across the bottom.

Trump has repeatedly blamed the problems on vandals, claiming without publicly providing evidence that people had used a knife or blade to make a 250-foot gash in the surface and poured destructive chemicals into the water.

He said Sunday that repairs would begin after he inspected the pool.

'Work will begin immediately on fixing the seriously vandalized Reflecting Pool,' Trump wrote. 'I just inspected it, and could only say to myself, and those gathered around me, WOW, who would do such a thing?'

The president said contractors might have to drain much of the pool again to carry out the repairs.

'We met with contractors today, will probably be forced to release and drain much of the water in order to do the necessary repairs, but will have them done as quickly as possible,' Trump wrote.

On Monday morning, Trump warned that anyone found damaging the site could face a decade behind bars.

'Of the MANY Statues and Fountains that we rebuilt, renovated, cleaned, and fixed, the only one that was Vandalized was the Reflecting Pool, which is being taken care of, ASAP!' he wrote.

'Please remember that there is a 10 year prison sentence for the destruction, or even the attempted destruction, of such things - Which will be fully enforced!'

The National Park Service's law-enforcement arm said five people had been arrested for vandalism and five others had received federal citations.

One of those arrested was David Hearn, 67, a former Olympic canoe racer from Bethesda, Maryland, who said he had stopped at the monument during a long bike ride to inspect the new coating.

Hearn said he leaned down and briefly touched a loose piece of paint that remained attached to the pool.

'I'm a curious citizen,' he said. 'I reached down to see what it felt like. It was very rubbery.'

He said he was detained by National Guard troops and US Park Police for five hours before being released Friday night. Hearn faces a misdemeanor charge of destruction of government property and has a court date next month.

Hearn denied damaging the surface.

'I didn't destroy or break or peel anything,' he told The Washington Post. 'By the time I realized what was going on, I was being put in handcuffs.'

He added: 'I reached in there, and I was able to grab the end of that flapping piece, the already peeling piece. It was still attached to the bottom. I didn't remove anything.'

Photographers captured workers pumping green algae and flakes of blue paint from the water on Friday. 

In one section of the pool, the word ‘TRUMP’ had been traced into the green scum over the patchy blue floor.

Critics have questioned the cost of the Reflecting Pool work, estimated by US media at more than $14million, as well as the process used to award contracts.

Trump, however, has insisted the work was successful before the alleged sabotage.