Google will delay its move to new UK headquarters in London's King's Cross as the company aims for more ambitious construction plans.

The search giant had expected to open its new premises in 2016, as part of a construction deal expected to be worth up to £1 billion.

Under original plans, the building, to be situated behind the revamped King's Cross station, was to contain features such as a swimming pool and a running track on its roof.

However, Google now claims that the plans for development were not ambitious enough, and will push its project team to create an improved plan.

Joe Borrett, head of real estate and construction at Google, said: "We have a great plan for the new building, but we want to challenge ourselves to do something even better for Google, King's Cross and for the local community."

The firm originally announced in January that it bought the property rights to develop a one million square foot offices area behind the King's Cross station, with work set to be completed by 2016. The move will see Google consolidate other UK offices, bringing together staff from its offices in Victoria and Holborn. Google also owns premises in London's east London Tech City.

Google's vice president for northern and central Europe, Matt Brittin, said that the plans signalled a "big investment" in the UK by Google.

"It's good news for Google, for London and for the UK," said Brittin.