Most Asian currencies eased and stocks advanced on Thursday, amid some caution among investors as they assessed the potential economic fallout from the Omicron coronavirus variant, while the South Korean won firmed on increased bets of a rate hike.

The United States confirmed its first case of the variant overnight, unsettling Asian financial markets that were already on edge due to its likely impact on the region's nascent economic recovery.

Equities saw diverging movements, with early losers paring their declines. Stocks in Singapore and Thailand fell just 0.2%, while Jakarta shares rose 1%.

The Indonesian rupiah, and Malaysia's ringgit eased 0.2% each, while the Thai baht dropped 0.4% to a seven-week low.

"Omicron is becoming a game of snakes and ladders," DBS Group Research analysts wrote in a note.

"For now, things could get worse first because more weeks of data will be needed to ascertain if Omicron is deadly or mild... The risk of more countries joining Austria in ordering lockdowns cannot be ruled out."

Adding to worries in Asia, South Korea reported its first five cases of the variant, with total COVID-19 infections in the country touching a record high despite stricter border curbs.

Seoul equities, however, rose 1.6% as they shrugged off negative headlines and continued to bask in the robust export and factory output data reported by the Asian trade bellwether on Wednesday.

The won added 0.3% to 1,175.90 per dollar, up for a fourth day, after November's consumer inflation accelerated to a decade high, coming in above the central bank's 2% target for an eighth straight month.

"This supports the path towards further tightening (by the Bank of Korea), putting the January meeting on watch for further rate hike," said Yeap Jun Rong, market strategist at retail trading platform IG.

The baht bore the brunt of investor panic over the variant that could potentially derail the reopening plans of tourism-reliant Thailand. It has fallen in nine of the last 10 days.

In the Philippines, equities rose 1.3% to see their best trading day in almost one month, rebounding from a 3.5% drop in the previous session.

Highlights

Indonesian 10-year benchmark yield was up 7.7 basis points at 6.37%??

Singapore's 10-year benchmark yield was down 6.4 basis points at 1.67%

Eyes were also on the decision by oil producing club OPEC and its allies on how they will manage supplies amid concerns of fuel demand due to the Omicron's spread.