Markets in Asia were mostly higher on Tuesday as investors awaited the start of a closely-watched meeting by the U.S. Federal Reserve, set to kick off later stateside. Shares in mainland China rose on the day. The Shanghai composite was up slightly at 2,890.16 and the Shenzhen component gained 0.27% to 8,804.32, while the Shenzhen composite was higher by 0.163% to 1,504.57. In Hong Kong, the Hang Seng index added more than 1%, as of its final hour of trading, with shares of Chinese tech heavyweight Tencent jumping more than 1.5%. Over in South Korea, the Kospi gained 0.38% to close at 2,098.71 as shares of biopharmaceutical firm Celltrion rose 1.46%. Meanwhile, the in Australia added 0.6% to end its trading day Down Under at 6,570.00. Japanese stocks bucked the overall trend. The Nikkei 225 slipped 0.72% to close at 20,972.71, as shares of index heavyweights Fast Retailing, Softbank Group and Fanuc fell. The Topix index also declined 0.72% to end its trading day at 1,528.67.

Central bank watch

The Fed is scheduled to start a two-day monetary policy meeting on Tuesday stateside. Expectations for any policy changes are low, but investors will look for clues about potential rate cuts this year. "Recent speeches by Fed officials, including Fed chair Jay Powell, have indicated a growing wariness of the inflation outlook and a willingness to act if required. We expect the (Federal Open Market Committee) to formalise this view on Wednesday by hinting that near‑term cuts to the Fed funds rate are coming. We expect the Fed will cut the Fed funds rate in December, but the risk is skewed to earlier cuts," Kim Mundy, currency strategist at Commonwealth Bank of Australia, wrote in a note. The Fed will make its monetary policy announcement on Wednesday. One economist told CNBC that other central banks such as those in Japan and Indonesia, also set to have their own meetings later in the week, could take direction from the Fed. "If the Fed is easing, it certainly means that they expect (that) the U.S. economy ... is slowing. If the U.S. economy is slowing, then very likely the global economy will be feeling that ... pain as well," Steve Cochrane, chief Asia Pacific economist at Moody's Analytics, told CNBC's "Squawk Box" on Tuesday. That, he said, would give the central banks regionally "a chance to ease as well and try to add some stimulus."

US-China trade

Meanwhile, on the U.S.-China trade front, hundreds of businesses stateside are attempting to send a message to U.S. President Donald Trump's administration to discourage them from increasing tariffs on China. That comes as U.S. Commerce Secretary Wilbur Ross says Trump is "perfectly happy" to impose new tariffs on China if the two economic powerhouses don't "make a deal."

Currencies and oil