By Shivangi Lahiri and Himanshi Akhand

Jan 31 (Reuters) - The South Korean won and the Malaysian ringgit fell most among Asian currencies on Friday as investors assessed the possibility of new tariffs on Canada, Mexico and possibly China under U.S. President Donald Trump.

The ringgit MYR= slipped 0.7% and was set for its weakest trading session in six weeks, while the won KRW=KFTC dropped 1.6%.

The dollar index was higher ahead of Feb. 1, the date on which Trump has threatened to impose 25% tariffs on imports from Canada and Mexico.

Trump has also threatened a 10% tariff on goods imported from China.

Mexico, Canada and China are the United States' three largest trading partners, accounting for more than $2.1 trillion in annual imports and exports.

The Mexican peso MXN= last traded marginally higher, after a 1% fall in a volatile session on Thursday, while the Canadian dollar CAD= languished near a five-year low.

Markets in China were closed for the Lunar New Year holidays.

Analysts at Barclays believe the tariff threats to emerging markets currencies are "merely delayed".

"Many Asian currencies have outperformed, suggesting risks of relatively more risk of weakness should tariff threats intensify against China," they said in a report.

The analysts see scope for the Thai baht THB=TH and the Philippine peso PHP= to depreciate further. They also see risks to the won, ringgit and the Singapore dollar SGD= given their vulnerability to sectoral tariffs and high direct and indirect export shares to the U.S.

The baht, peso, and Singaporean dollar were last marginally lower.

The Indonesian rupiah IDR= weakened 0.3% and was set for its worst monthly drop since July.

The Indian rupee INR= slipped to an all-time low with traders suggesting the Reserve Bank of India (RBI) probably stepped in to support the currency.

Regional equity markets were mixed, with shares in Seoul .KS11 dropping as much as 1.6%, following a four-day holiday break.

The decline was led by major chipmakers which caught-up to the global tech rout that was triggered earlier this week after China's DeepSeek rolled out its cheap AI model.

Singapore's benchmark index .STI rose up to 2% to a four-week high on the back of a 2.3% rise in its banking sub-index.

DBS Group DBSM.SI, the biggest bank in Southeast Asia, rose 3.1%.

Stocks in Thailand .SETI slipped 0.8%. Indonesian equities .JKSE added 1.2%, after falling 1.3% in the previous session.

Investor focus is now on the December U.S. personal consumption expenditures (PCE) price index report due later in the day. They are also awaiting a slew of regional inflation data next week, including from Indonesia, the Philippines and Thailand.

HIGHLIGHTS:

** Philippines cbank sees January inflation at 2.5% to 3.3%

** Thailand's economy may underperform with consumption weak, warns central bank chief

** Indonesia's FDI at $55.3 bln in 2024

(Reporting by Shivangi Lahiri and Himanshi Akhand in Bengaluru; Editing by Kate Mayberry)

((shivangi.lahiri@thomsonreuters.com))