Japan is considering expanding a controversial program that now offers workers from China and elsewhere permits to work for up to three years, as the world's fastest-aging nation scrambles to plug gaps in a rapidly shrinking workforce.

Prime Minister Shinzo Abe's Liberal Democratic Party on Tuesday submitted a proposal to let workers to stay for up to five years, relax hiring rules for employers and boost the number of jobs open to them.

"We will strengthen the governance of the program," LDP lawmaker Yasuhisa Shiozaki, who authored the proposal, told reporters. "We are aware of the concerns and we allowed people who had objections to voice their objections."