Emerging Asian currencies weakened against the dollar on Monday, as uncertainty around an initial Sino-US trade deal offset upbeat economic data from China.

Caution pervaded in markets, with a deadline on an imposition of additional 15% tariffs on Chinese products by the United States just two weeks away, and Beijing demanding scrapping of existing tariffs as part of the trade deal.

Data over the weekend showed factory activity in China unexpectedly returned to growth in November for the first time in seven months, as domestic demand picked up on Beijing's accelerated stimulus measures to steady growth.

"I think developments on a phase one trade deal is still something markets pay more attention to. The improvement in China's PMI were welcomed... but it doesn't change the fact that Chinese growth will still be impacted by the ongoing trade war," Khoon Goh, head of Asia research at ANZ Banking Group (Singapore) said.

South Korea's won strengthened as much as 0.3%, before erasing gains. The trade-reliant economy's exports in November plunged for a 12th month in a row.

China's yuan edged up after the central bank's governor said that China would not resort to competitive devaluation of the yuan and would aim to keep it broadly stable.

The Malaysian ringgit, Singapore dollar and the Thai baht eased 0.1% each.

Thailand's headline consumer price index rose 0.21% in November, but remained below Bank of Thailand's 1%-4% target range for a sixth straight month.

A jump in oil prices put pressure on the region's net importers. The Indonesian rupiah weakened 0.2%, while the Philippine peso dipped 0.1%.

Indonesia's annual inflation rate slowed for a third straight month in a row, its weakest pace since April, the country's statistics bureau said on Monday.

The Indian rupee was little changed at 71.71 per dollar.

Data on Friday showed India's annual economic growth slowed to its weakest pace since 2013 in the July-September quarter, putting pressure on Prime Minister Narendra Modi to speed up reforms.

Markets now await Reserve Bank of India's (RBI) policy meeting this week, where a 25 basis points cut is widely expected, though economists now see only a marginal impact from monetary easing to the economy.

"We think the economy needs more than fiscal or monetary stimulus," analysts at ING said in a note on Sunday.

"Accelerated economic and banking sector reforms and strong infrastructure investment are needed to regain the 7%-8% growth potential."

India will unveil a series of infrastructure projects this month as part of a plan to invest 100 trillion rupees ($1.39 trillion) in the sector over the next five years, the finance minister said on Saturday.