A plan to build the tallest building on earth - the $28.5 billion Kingdom Tower in Jeddah, western Saudi Arabia that will stand 1.6km high - has reportedly been approved.

It will take a 12-minute elevator ride to get to the top of the building in Obhur, about 32km north of Jeddah City on the Red Sea's eastern coast.

Dubai's Burj Khalifa is the world's tallest building, but is set to be doubled in height by the planned Kingdom Tower in Saudi Arabia. Credit:Reuters

The 1609-metre Kingdom Tower will exceed Dubai's 1000-metre Nakheel Harbour and Tower, the construction of which has reportedly been put on hold.

The Kingdom Tower, designed by American Adrian Smith, will be nearly double the height of the tallest building on the planet, the 828-metre Burj Khalifa in Dubai, also designed by Smith.