Japan's estimate for the amount of debris from the 2011 quake-tsunami disaster that will reach North America later this year has sharply increased, a report said Friday.

Some 221,000 tons are set to reach the North American coastline by October, according to data from the Ministry of Environment, Kyodo news agency reported.

In November the ministry had said 33,000 tons of debris would complete its journey across the Pacific by June.

But the new forecast estimates 30,000 tons to arrive by April, 105,000 tons by June and 173,000 tons by August.

Japanese government data has estimated 1.5 million tons of debris were swept away from the northeast coastal prefectures of Iwate, Miyagi and Fukushima after the March 11, 2011 tsunami that followed a 9.0-magnitude earthquake.

The quake-tsunami, which left nearly 19,000 people dead, is thought to have swept in total some five million tons of shattered buildings, cars, household goods and other rubble into the sea.

About three-and-a-half million tons sank immediately, leaving a massive amount of plastic, timber, shipping containers, industrial scrap and innumerable other objects to float deeper into the ocean.

Marine experts poring over the disaster have said the floating trash adds significantly to the Pacific's already worrying pollution problem.