Asian shares subdued after Bannon departure as US-South Korea military drills begin
Behrouz Mehri | AFP | Getty Images. Asia markets closed mixed on Monday as investors digested political developments in Washington while U.S.-South Korea joint military drills kicked off. · CNBC

Asia markets closed mixed in Monday trade as investors digested political developments in Washington while U.S.-South Korea joint military drills kicked off.

Japan's Nikkei 225 (Nihon Keizai Shinbun: .N225) slid 0.40 percent, or 77.28 points, to close at 19,393.13, as gains in oil stocks were offset by softness in most automakers, financials and technology names. The benchmark index had fallen to its lowest levels in more than three and a half months earlier in the session.

Across the Korean strait, the Kospi (Korea Stock Exchange: .KS11) shed 0.14 percent, or 3.37 points, to close at 2,355, as U.S.-South Korea military exercises began.

The joint military drills, which will take place from Aug. 21 to Aug. 31, come on the back of a ramp up in geopolitical tensions earlier this month after a heated exchange of rhetoric between President Donald Trump and Pyongyang.

Down Under, the S&P/ASX 200 (ASX: .AXJO) declined 0.37 percent, or 21.212 points, to finish the session at 5,725.900, with weakness in the health care and telecommunication services sub-indexes leading losses. The heavily-weighted financials sub-index traded lower by 0.29 percent.

Greater China markets bucked the downward trend to climb higher. Hong Kong's Hang Seng Index (Hong Kong Stock Exchange: .HSI) gained 0.48 percent by 3:15 p.m. HK/SIN. On the mainland, the Shanghai Composite (Shanghai Stock Exchange: .SSEC) advanced 0.57 percent, or 18.5977 points, to close at 3,287.3220 and the Shenzhen Composite rose 0.745 percent, or 14.1648 points, to end at 1,916.4186.

Steve Bannon on Friday became the latest high-ranking official to leave the White House when he vacated the role of President Donald Trump's chief strategist. Media reports said Bannon's resignation had been submitted earlier in August, but its announcement had been pushed back due to violence from a white nationalist rally in Charlottesville, Virginia.

While the ouster resulted in a positive reaction in risk assets — major U.S. indexes had fallen sharply last Thursday on rumors that National Economic Council Director Gary Cohn could leave — its impact on markets was short-lived, one expert said.

"From a market perspective ... Bannon's departure doesn't change Trump's strong views on immigration, border security and trade protection," National Australia Bank currency strategist Rodrigo Catril said in a Monday note.

On Wall Street, stocks closed above session lows on Friday after news of Bannon's departure, with the Dow Jones industrial average declining 0.35 percent, or 76.22 points, to close at 21,674.51.