
The US Ambassador to Britain Woody Johnson has shown off his new £750 million embassy building in south London.

The structure is believed to be the most expensive embassy building in the world and features state-of-the-art security systems.

The new building is expected to be officially inaugurated in February during President Donald Trump's planned working visit to the UK.

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The US State Department announced the competition to design the 12-storey building back in 2008. It was won by architecture firm KieranTimberlake in 2010 which is headed by Stephen Kieran and James Timberlake in Philadelphia

A wall inside the embassy building shows the names of all the former ambassadors from the United States. The ambassadorship has been held by various notable politicians, including five who would later become presidents: John Adams, James Monroe, John Quincy Adams, Martin Van Buren and James Buchanan

The new building is designed to make the most of the space and natural light to encourage 'transparency and openness'. Pictured: The Canyonlands Garden, which represents the Grand Canyon and the south west desert landscapes of the US

Among one of the features at the US Embassy is this circular bar with stunning views overlooking the London skyline. The bar has raised seats around the outside with large glass windows providing an expansive view of the city

This sculpture by British artist Rachel Whiteread depicts a typical home in the United States built in the 1950s. The sculpture has been placed in the consular lobby inside the US embassy

This map shows the location of the new embassy in Nine Elms, London. The area was formerly mainly industrial but is now becoming more residential and commercial in character. It is dominated by Battersea Power Station, various railway lines and New Covent Garden Market. Also in the area is the Battersea Dogs and Cats Home

This is the stunning new riverside embassy building constructed by the US government at a cost of £750 million. The Houses of Parliament and the London eye can be seen in the distance

The state-of-the-art building has been unveiled today by the US Ambassador Woody Johnson who said the £750 million embassy was a 'signal to the world' that the special relationship between Britain and the US is as strong as ever.

He said he would like to have President Trump at the embassy's official opening in February. The building is protected by a moat and features a sculpture by British artist Rachel Whiteread which depicts a typical home in the United States built in the 1950s.

Mr Trump had tasked him with strengthening the special bond between the two countries, he said, adding that the president recognised the UK was 'the gateway to Europe'.

He said: 'President Trump wants to work more closely than ever with the UK, and it will make both of our countries more prosperous and secure.

'So the new embassy is a signal to the world that this special relationship that we have is stronger and is going to grow and get better.

Ambassador Woody Johnson, pictured, said he hoped President Donald Trump will attend the embassy's official opening

'He mentioned that to me himself ... He said "I want you to make it stronger", and I intend to do that if I can.

'We are looking forward to welcoming the president when he comes over here. I think he will be very impressed with this building and the people who occupy it.'

He said the president's schedule is difficult and it's not clear when he will visit. Trump has accepted an invitation for a state visit to be hosted by Queen Elizabeth II, but no date has been set.

Officials say it would have been prohibitively expensive to renovate the Grosvenor Square embassy, which opened in 1960, and update it with modern security features.

The new building, with its distinctive cube shape, is nearly twice as large as the Grosvenor Square facility. It is the single most expensive embassy building ever built by the United States, Ambassador William Moser said, even though U.S. diplomatic compounds in Kabul, Afghanistan and Baghdad, Iraq cost more.

Moser, who supervises overseas building construction for the State Department, said the money for the site and its development was generated by selling other U.S. government properties in Britain.

'It was built with no taxpayer dollars,' he said.

The 12-storey building offers a commanding view of the Thames and its design emphasises sustainability, including the use of water runoff to form a waterfall.

The new building features 518,000 square feet of space - far more than the 225,000 square feet in Grosvenor Square. However, three of the nine floors at the old building are below ground to confirm with stringent height restrictions in Mayfair.

Acclaimed US architect firm Kieran Timberlake was selected to design the new, carbon-neutral embassy south of the river.

In environmental terms, it will be nearly self-sufficient in energy production and even capable of operating off-grid 'for an extended period', according to officials.

Unlike most glass office buildings, which appear slick and hard-edged, this one has been fitted with lightweight plastic scrims attached to the facade like boat sails.

The scrims do triple a duty. They are made from the same 'Etfe' fabric that was quilted on to the Beijing Watercube for the Olympics, they have been embedded with photovoltaic cells that convert sunlight into energy.

They will also act as sunscreens to keep interiors from overheating. And because the fins are pinched at regular intervals, they create a rippling, sculptural effect on the glass surface.

One of the main security features of the new embassy is a moat between the building and the River Thames to the north. Construction of the building started in 2013 and has been completed more or less on time

The Embassy has been designed to reduce the impact of peak energy demands to reduce its environmental impact. Pictured: The Pacific Forest Garden in the 12-storey building in Nine Elms

A spokesperson for the embassy said the glass structure 'gives form to the core democratic values of transparency'. Pictured: The main lobby with the names of previous ambassadors on the wall

Ambassador Johnson open the Embassy today for a special tour in advance of his staff moving in next month. Mr Johnson said: 'President Trump wants to work more closely than ever with the UK, and it will make both of our countries more prosperous and secure'

He added: 'We are looking forward to welcoming the president when he comes over here. I think he will be very impressed with this building and the people who occupy it.'

Flanked by the American and UK flags, Mr Johnson spoke eloquently about the embassy's attachment to the former site, which he said had been home to the US in some form for 200 years.

For more than half a century, the embassy has been located in the Grade II-listed London Chancery Building in Grosvenor Square, Mayfair.

This corridor features a photograph of Winfield House garden, the official residence of the US Ambassador to the UK. The new embassy which was funded by the sale of US property in London

These glass tiles featuring the US State Department seal are part of an installation in a cafe area inside the Embassy building. Mr Johnson said: 'The new embassy is a signal to the world that this special relationship that we have is stronger and is going to grow and get better'

But the diplomatic mission is moving across the River Thames to the new 12-storey cube-shaped building on a 4.9-acre site in Vauxhall, and will formally open on January 16.

Construction on the building has taken four years and will replace the existing embassy on Grosvenor Square which will be sold off as a hotel.

The old embassy was built in 1960 of stone and concrete, although Grosvenor Square was known as 'Little America' during World War II and was home to the military headquarters of General Dwight D Eisenhower.

The U.S. State Department ran a competition to design the new building in 2008. It described the embassy as 'a physical manifestation of the long-term commitment to the special relationship between the United States and the United Kingdom'.

The increased space in the new building will make it easier for visitors to attend their interviews for US visas. The 12-storey building offers a commanding view of the Thames and its design emphasises sustainability, including the use of water runoff to form a waterfall

Work is continuing preparing the new building for the arrival of 800 staff on January 16 ahead of the formal opening. The US State Department ran a competition to design the new building in 2008

The US Embassy is moving from its existing location on Grosvenor Square, pictured, which has deemed as less than secure. The old embassy was built in 1960 of stone and concrete, although Grosvenor Square was known as 'Little America' during World War II and was home to the military headquarters of General Dwight D Eisenhower

According to the US State Department, the building has been funded by the sale of other property in London. The embassy features six interior and exterior gardens. The interior gardens are all inspired by a different region of the country

Ambassador Johnson said Grosvenor Square had been home to the US in some form for 200 years. The glass structure 'gives form to core democratic values of transparency, openness and equality' a State Department briefing document said

The embassy features six interior and exterior gardens. The interior gardens are all inspired by a different region of the country, including the Canyonlands, the Gulf Coast, the Midwest, the Potomac River Valley, the Pacific Coast and the Mid Atlantic.

According to the officials at the embassy: 'The garden plantings not only represent the diversity of the United States’ landscape, they were also selected for their capacity to thrive in specific garden orientations.'

The glass structure 'gives form to core democratic values of transparency, openness and equality' a State Department briefing document said. Its £750m construction was wholly funded by the sale of other properties in London.

Workers are completing the final touches inside the massive project which will be opened to the public in the new year. Pictured: The Department of The Treasury logo inside the new United States Embassy

The 518,000 square foot building is the first embassy in Nine Elms which is likely to become a new diplomatic centre. According to the US Embassy, the architect firm's design had to consider environmental as well as security concerns when building the structure

The building has been designed to minimise its impact on the environment and has been fitted with solar panels

Ambassador Johnson said President Trump viewed Britain as his gateway into Europe and wanted to improve relations

The building has magnificent views over the River Thames from its new location in Nine Elms. Pictured: The view from an office toward River Thames. The building will have solar power as well as natural gas fueled combined heating

The 800 staff at the US Embassy will move into the new building in Nine Elms in the new year ahead of Donald Trump's visit The building has special sails on the outside with prevent the interior overheating and make the most of natural light

According to the US Embassy, the architect firm's design had to consider environmental as well as security concerns when building the structure.

Officials said: 'Energy and environmental design issues have been balanced with the overall project goals of openness, diplomacy, functionality, security and value. Employing technologies that use alternative energy sources and reduce peak energy demand and overall energy consumption represents a commitment to sustainable design. These strategies also provide enhanced occupant comfort which has been shown to contribute to better functionality and productivity by improving employee satisfaction.'

The building will have solar power as well as natural gas fueled combined heating and a biomass heating scheme providing heat to the surrounding community.

The building does not have a high security barrier around the perimeter. Instead there are some public gardens with benches on the edge of the property, then a pond to keep unauthorised people from approaching the new building south of the River Thames.

James Timberlake, of Kieran Timberlake, said: 'It meets and exceeds all the security requirements. We are using elements of landscaping that have been around for centuries and centuries.

'But it's not a fortress. We are able to use the landscape as a security device. There's no wall and no fences.'

The British-U.S. relationship has been tested in recent months.

Britain's Prime Minister Theresa May was the first foreign leader to visit the White House after Trump's surprise election in November 2016.

While the two leaders have committed to strengthen trade links and spoken regularly, their governments have disagreed on several issues, such as Trump's decision to decertify Iran's compliance with a multilateral nuclear deal, and his move to recognise Jerusalem as the capital of Israel.

Earlier this month, May publicly criticised Trump for reposting British far-right anti-Islam videos from his Twitter accounts. He responded with a rebuke, telling May to focus on Islamic extremism in Britain.

Ambassador Johnson hopes President Trump will be able to attend the official opening of the embassy in February. James Timberlake, of Kieran Timberlake, said: 'It meets and exceeds all the security requirements. We are using elements of landscaping that have been around for centuries and centuries'

The new building is expected to open next month with the first staff moving into the building early next month. Britain's Prime Minister Theresa May was the first foreign leader to visit the White House after Trump's surprise election in November 2016