Foreign Minister Seiji Maehara called Wednesday for appropriate rules to accept more foreign workers ahead of an anticipated severe labor shortage in rapidly aging Japan, warning that China's eventual "supergraying society" could soak up migrant workers.

In a speech at the Japan Foreign Trade Council Inc., Maehara deplored the fact that only a few Indonesian and Filipino nurses, who have come to Japan since 2008 under bilateral free-trade agreements, have passed the Japanese national qualification examinations. Those who fail to qualify in a certain period of time must return home under the current accords.

More than 1,000 nurses and caregivers have come to Japan from the two countries with the aim of becoming qualified to work here, but only two Indonesians and one Filipino have so far passed the exam.

"(The low qualification rate) is no laughing matter. We have to broadly look at our strategic environment," Maehara said. "China now basically adopts a one-child policy and the country with 1.3 billion people is certain to become a superaging society."

"If China seeks nurses and caregivers from neighboring Asian countries in 10 to 20 years' time, Japan, which already suffers from a shortage of staff, will compete with a country that has 10 times more people to secure medical workers," he said.

The foreign minister criticized the health ministry for being reluctant to accept more foreign nurses and caregivers and prioritizing the employment of existing qualified Japanese who are not working right now.