Researchers estimate that Japan could by 2030 face a shortfall of 630,000 foreign workers required to cover the nation's chronic labor shortage.

The Japan International Cooperation Agency's Ogata Sadako Research Institute for Peace and Development conducted a study focusing on 13 countries from where many people come to Japan to work. They include Vietnam.

The study hypothesizes that capital investment will reduce the need for human labor. Under the best-case scenario, Japan needs 4.19 million foreign workers in 2030, but will actually have 3.56 million.

The study cites narrowing wage gaps between Japan and countries where workers typically come from, and also declining birthrates in those countries.

The study shows that the required amount of foreign workers in 2040 will account for more than 10 percent of all people aged 15 to 64 in Tokyo and eight other prefectures. The figure in the capital is estimated to exceed 18.9 percent.

JICA Vice President Shishido Kenichi says other countries are also trying to acquire foreign workers, and that fewer people will be willing to work in Japan, even if visa requirements are relaxed. He says the country needs to create a society in which foreigners feel they can settle.