US President Donald Trump has defended his decision to demolish part of the White House East Wing to build a ballroom, calling the construction “music to my ears”, despite mounting criticism of the project.

Speaking to senators from his Republican Party at the White House on Tuesday, Trump also said: “You probably hear the beautiful sound of construction in the back… When I hear that sound, it reminds me of money.”

Trump, a former property developer, is spending $250m (£186m) on a new, 90,000 sq ft (8,360 sq m) ballroom to host parties, state visits and other events.

But since work began on Monday, a number of critics have spoken out – among them his one-time rival, Hillary Clinton.

Also on Tuesday, the leader of the National Trust for Historic Preservation, a Washington non-profit organisation that protects historic US sites, wrote a letter to White House officials saying she was “deeply concerned” by the project.

The letter said the size of the new construction would “overwhelm the White House itself… and may also permanently disrupt the carefully balanced classical design of the White House with its two smaller, and lower, East and West Wings”.

The trust asked Trump to pause demolition work, arguing that the White House was a national historic landmark and that officials needed to hold a public review process of the plan for the ballroom.

Another group, the Society of Architectural Historians, also said it had “great concerns” about the project, similarly calling for a review process because of the size of the planned construction.

The White House has hit back at its critics, writing in a news release that “unhinged leftists” were “clutching their pearls over President Donald J Trump’s visionary addition of a grand, privately funded ballroom to the White House – a bold, necessary addition”.

Trump officials have also insisted that the renovation will not cost US taxpayers any money, and that there is nothing inappropriate about soliciting private donations to help pay for it, as Trump has been doing.

Many Democrats have also lambasted the renovation, including Clinton, who ran against Trump for the U presidency in 2016.

Addressing her followers on X, whe wrote that the White House was not Trump’s house. “It’s your house. And he’s destroying it.”

Since it was built in the late 1700s, the White House has undergone a number of renovations and restorations. In 1948, then-President Harry Truman gutted the inside of the White House as it was at risk of collapsing, adding a balcony to the exterior.

Over the years, presidents have added swimming pools, bowling alleys and other touches – though critics have highlighted that Trump’s additions appear to be the biggest alterations to the White House exterior in decades.

White House officials have said the project does not require sign-off from the National Capital Planning Commission, an agency that oversees construction and renovations to government buildings in Washington and is chaired by a Trump aid.

But a former chair of the commission, L Preston Bryant Jr, told the Associated Press that previous administrations have worked closely with the agency on big construction projects, starting with an “early consultation” before the renovation began.