The policy adjustments announced by the Bank of Japan on Friday may indicate there are limits to the drastic monetary easing policy the central bank launched to stoke 2 percent inflation.

The moves to increase the BOJ's purchases of exchange-traded funds and broaden the average maturity of its Japanese government bond holdings appear aimed at providing additional support for Prime Minister Shinzo Abe's ongoing efforts to increase wages and capital investment and restructure the economy.

Under the new program, the BOJ will purchase ETFs composed of stocks issued by companies that are "proactively making investment in physical and human capital."