Most Asian stock market indices were trading lower on Tuesday (17 January), with the Shanghai Composite down 0.75% at 3,080.04 as of 5.14am GMT, ahead of Theresa May's Brexit speech later in the day.

The prime minister is expected to unveil 12 negotiating objectives for the UK government. She is also expected to reject a "half-in, half-out" Brexit and stress that she wants the European Union to succeed after Brexit, while calling for a "new and equal partnership" with just months to go before the actual Brexit negotiations begin.

Analysts said this had reinforced fears of a 'hard Brexit' keeping investors cautious, leading to a bearish trend in the markets.

"The PM is expected to walk a fine line between providing enough information on the government's intentions, without necessarily showing too much of Britain's negotiating hand ahead of official discussions with the EU," Rodrigo Catril, a strategist with the National Australia Bank, was quoted as saying by CNBC.

The bearish trend also comes ahead of the inauguration of Donald Trump as US president on 20 January. A few analysts opined that uncertainty over the US president-elect's future policies was also pushing the markets lower.

"Markets affected by the twin political black swans of 2016 - the Brexit vote and Trump win - remain volatile and uncertain," David Croy, a strategist with ANZ, was quoted as saying by Reuters.

Indices in the region were trading as follows at 5.26am GMT:

CountryIndexPriceUp/Down%Change
Hong KongHang Seng Index22,797.89Up0.35%
JapanNikkei 22518,889.60Down1.08%
South KoreaKOSPI2,074.76Up0.51%
IndiaBSE27,256.36Down0.12%
AustraliaS&P/ASX 2005,699.40Down0.85%

On 16 January, the FTSE 100 Index closed 0.15% lower at 7,327.13, while the S&P 500 index which did not trade yesterday, closed 0.18% higher at 2,274.64 on 13 Jan.

Among commodities, oil prices were mixed. As of 12.17am EST, WTI crude oil was trading 0.10% higher at $52.42 (£43.37) a barrel, while Brent crude was trading 0.32% lower at $55.68 a barrel. This followed news that Saudi Arabia would continue to reduce production even as a report forecast US output to rise again in 2017.