Investors in Asia-Pacific markets are awaiting the Federal Reserve's rate decision, with markets opening mixed.

• Asian investors closely monitor key economic data from Japan and the Indonesian central bank's rate decision, while awaiting the Federal Reserve's key rate cut decision in the US on Wednesday.
• Markets in South Korea and Hong Kong are shut today, while markets in mainland China will resume trading following a three-day national holiday.

On Wednesday, Asia-Pacific markets opened with mixed results, mirroring the gains on Wall Street the previous day, where both the S&P 500 and the Dow Jones Industrial Average reached new highs.

The Federal Reserve's rate decision on Wednesday, as well as economic data from Japan and the Indonesian central bank's rate decision, will be closely watched by investors stateside.

Japan's imports and exports in August grew by 2.3% and 5.6%, respectively, from the previous year, but fell short of the Reuters poll estimates of 13.4% and 10% growth.

The Cabinet Office reported that Japan's private sector machinery orders decreased by 0.1% in July compared to the previous month, which was lower than the estimated 0.5% increase by Reuters.

The BI-rate decision by Bank Indonesia is scheduled for Wednesday, despite inflation being below the central bank's target range of 1.5%-3.5%.

Markets in South Korea and Hong Kong are shut today, while markets in mainland China will resume trading following a three-day national holiday.

Australia's S&P/ASX 200 fell 0.09% on open.

Japan's rose 1.22% while the broad-based Topix was 0.9% higher.

The CSI 300 futures for mainland China were slightly higher at 3,163 compared to their previous close of 3,159.25.

In the U.S., the S&P 500 reached an intraday high before closing below its session high but still finished higher on the day at 5,634.58. Meanwhile, the Dow Jones Industrial Average fell 0.04% to close at 41,606.18 after also setting a new record during the session.

The Nasdaq Composite added 0.2% to 17,628.06.

In August, retail sales increased by 0.1% compared to the previous month, contrary to the Reuters poll forecast of a 0.2% decline, as assessed by Wall Street.

—CNBC's Hakyung Kim and Samantha Subin contributed to this report.