Philippine stocks led losses in Asian equity markets on Wednesday, while currencies traded flat as broader sentiment wavered on weak China data and uncertainty in the high-stakes US Senate election in Georgia.

South Korea's KOSPI, however, smashed past the 3,000 level for the first time in early morning trade before giving back gains to fall 0.2%.

Manila stocks plunged almost 3% and were set for their worst day since August, while Malaysia and Indonesia shares slipped 1% and 0.8%, respectively, after US stock futures turned negative as the vote count in Georgia hinted at a tight race.

The outcome of the runoff vote to elect two senators will determine control of the chamber and have an impact on incoming President Joe Biden's economic policies, although a final result is not expected at least before Wednesday morning in the United States.

"Market sentiment across Asia-Pacific turned sour as races in the Georgia runoff election are tight, creating much political uncertainty," said DailyFX strategist Margaret Yang.

"Fiscal stimulus and infrastructure spending are on top of the Democrats' agenda, which in turn will likely influence the dollar and bring a cascading effect on the broader asset classes."

Asian stocks were also hit by the region's top trade partner China posting a slow uptick in services sector activity in December as sporadic coronavirus outbreaks weighed on business growth, a private sector survey showed.

China, which has powered the region's economic recovery since July, saw its shares fall 0.2%, while the yuan dropped 0.1%.

Most Asian currencies were tepid despite a weak greenback as uncertainty over the US Senate election and its implications for the US dollar unnerved investors.

Singapore dollar, the Philippine peso were flat, while the Indonesian rupiah ticked up 0.1%.

However, losses in Asian currencies were capped as improving fundamentals in the region and an ultra-low interest rate environment kept them attractive, Yang added.