The estimated cost of dealing with the 2011 Fukushima nuclear crisis has doubled to nearly $190 billion, the government said Friday, underlining the challenge Japan faces in overcoming the world's worst nuclear disaster since Chernobyl.

Tokyo said it expects the total costs -- including compensation, decommissioning and decontamination -- to reach 21.5 trillion yen ($188 billion).

The figure is nearly double the previous estimate of 11 trillion yen made three years ago.

Tokyo's confirmation of the surging costs linked to the accident comes after public broadcaster NHK reported similar figures last week.

The estimates were hammered out by an expert panel that is working out how costs should be divided between the government, Fukushima operator Tokyo Electric Power (TEPCO) and others.

A massive undersea quake on March 11, 2011, sent a giant tsunami barrelling into Japan's northeastern coast, leaving more than 18,500 people dead or missing, and sending three reactors into meltdown at the Fukushima nuclear plant.

It was Japan's worst postwar disaster and the most serious nuclear accident since Chernobyl in 1986.

TEPCO faces a massive task of clearing highly radioactive spent fuel rods from its badly damaged reactors, and the entire decommissioning process is expected to take up to four decades.

It also has to pay compensation to residents, while the government will incur part of the costs for decontamination and building storage for contaminated debris.