MSCI's broadest index of Asia-Pacific shares outside Japan was down 0.48% and Japan's Nikkei N225 was down 0.25%. Chinese stocks also fell, with the blue chip CSI300 down 0.3%, while Hong Kong's Hang Seng index fell 0.79%.

The Japanese yen was weaker in early trade ahead of a Bank of Japan policy meeting later today that is expected to keep interest rates at ultra-low levels. The yen is currently trading at 157.1 per dollar.

The yen’s plunge to a 34-year low of 160.245 yen per dollar in late April triggered a series of interventions by Japanese authorities totaling 9.79 trillion yen ($62.25 billion). The yen, which is highly sensitive to U.S. Treasury yields, has fallen more than 10 percent against the dollar this year.

The US dollar is hovering near a one-month high thanks to the US Federal Reserve's dovish policy this week, while political uncertainty in Europe has kept the euro under pressure.