Asia-Pacific markets open mixed as investors await Federal Reserve's rate decision

Asia-Pacific markets opened mixed on Wednesday, following gains on Wall Street that saw both the S&P 500 and the Dow Jones Industrial Average reach new highs.

Investors await the Federal Reserve's rate decision due Wednesday stateside, and will also assess economic data from Japan as well the Indonesian central bank's rate decision.

Japan's imports and exports in August rose 2.3% and 5.6%, respectively, from a year ago, according to Japan's Ministry of Finance, both missing the Reuters poll estimates of 13.4% and 10% growth.

Japan's private sector machinery orders in July declined 0.1% from the previous month, according to data from the Cabinet Office, missing Reuters estimates of a 0.5% increase.

Bank Indonesia is set to meet Wednesday for a key BI-rate decision. The policy rate stands at its highest level since 2016, even as inflation has cooled to well within the central bank's 1.5%-3.5% target.

South Korea and Hong Kong markets are closed today while markets in mainland China will resume trade after a nationwide three-day holiday.

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

Japan's Nikkei 225 rose 1.22% while the broad-based Topix was 0.9% higher.

Futures for mainland China's CSI 300 stood at 3,163 slightly higher than their Friday close of 3,159.25.

Overnight in the U.S., the S&P 500 notched an intraday record before closing below session highs but still slightly higher on the day at 5,634.58. The Dow Jones Industrial Average fell 0.04% to close at 41,606.18 after touching a fresh record during the session.

The Nasdaq Composite added 0.2% to 17,628.06.

Wall Street assessed the latest retail sales which rose 0.1% in August from the previous month, compared to the Reuters poll forecast of a 0.2% decline.

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