Japan's unemployment rate fell to the lowest level in more than 25 years in May in the latest sign of a strengthening economy, government data showed Friday, but rising job availability underscored the shortage of workers amid a shrinking population.

The jobless rate stood at 2.2 percent, beating market forecasts to remain unchanged from 2.5 percent in April and hitting a low not seen since October 1992, according to the Ministry of Internal Affairs and Communications.

The job openings-to-applicants ratio climbed to the highest level in more than 44 years, rising to 1.60 from 1.59 the previous month, according to separate data from the Ministry of Health, Labor and Welfare. The ratio means there were 160 openings for every 100 job seekers.

Companies in the country are grappling with a deepening labor shortage as the rapidly aging population means fewer working hands, an issue that has raised concerns about the growth prospects for the world's third-largest economy.

In a bid to tackle the issue, Prime Minister Shinzo Abe and his Cabinet earlier this month approved a plan to welcome more low-skilled workers from abroad, pulling back from the government's reluctance to accept foreign labor.

Despite the tight labor market, wage growth has remained tepid, hindering the Bank of Japan's efforts to lift inflation to 2 percent.

The unemployment rate for men fell 0.4 percentage point to 2.4 percent, while that of women dipped 0.1 point to 2.0 percent.

"Labor market conditions are solidly improving," an internal ministry official said.

Japan had 66.73 million workers on a seasonally-adjusted basis, falling 0.3 percent, or 200,000 workers, from the previous month. Men increased by 90,000 to 37.25 million, while women dropped by 290,000 to 29.48 million.

"This fall was unexpected. It could be interpreted as workers, mainly women, leaving the labor market after temporarily participating in the January-March quarter," said Koya Miyamae, an economist at SMBC Nikko Securities Inc.

The number of unemployed people stood at 1.51 million, plummeting 12.2 percent, or by 210,000. The number of men without work decreased by 180,000 to 900,000, while women fell by 40,000 to 610,000.