It's an unusual sight. Tanks and other US military equipment parked alongside the Lincoln Memorial on Washington's National Mall.

The massive vehicles were carefully moved into position yesterday ahead of a major 4 July celebration planned for later today.

Soldiers had to lay planks of plywood on the street before driving the tanks into position so as not to damage the road surface. It's a big, expensive operation and a controversial one.

Ever since attending a Bastille Day celebration in France two years ago, US President Donald Trump has wanted a military parade of his own.

Previous attempts have failed amid concerns over cost, but today President Trump will get his wish.

The celebration, which the president has dubbed a 'Salute to America', will include a parade, flyovers by fighter jets and an elaborate fireworks display.

Mr Trump will address the gathering from the steps of the Lincoln Memorial.

The event has attracted a lot of criticism. Some argue that there shouldn't be such a focus on the military at an Independence Day event. The US armed services are traditionally honoured on other occasions such as Memorial Day and Veterans' Day.

There also concerns that President Trump is trying to politicise 4 July, which is typically a non-partisan celebration.

The White House said the president will focus his remarks on patriotism, not politics, but Democrats have warned that he'll use the address as a rally.

VIP tickets for the event have been given to the Republican National Committee and big political donors.

And then there's the cost. Critics have accused Donald Trump of using taxpayers' money to fund a vanity project.

The White House has not said what the final bill will be but The Washington Post has reported that the US Parks Service has diverted $2.5m of its funds to cover some of the costs.

President Trump has taken to Twitter to defend the expense.

"The cost of our great Salute to America... will be very little compared to what it is worth," he wrote.

"We own the planes, we have the pilots, the airport is right next door (Andrews), all we need is the fuel. We own the tanks and all."

President Trump has also insisted that it will be an important opportunity to honour and celebrate the US military.

Despite his reassurances, opponents are seeing this as another controversial move by a polarising president.

There will be protests at today’s event, with the famous Trump 'Baby Blimp’ expected to make an appearance.

Independence Day commemorates the Declaration of Independence in 1776 when the Continental Congress declared that the 13 American colonies were now free, independent and united.

But this year, that celebration of unity looks set to highlight the deep divisions that exist in the US today.