By Arundhati Dutta

Doubts about the trade talks emerged early last week, although optimism gradually returned as U.S. officials sounded more positive. Neither side, however, provided concrete details about headway in their trade talks.

On Saturday, Chinese state media said the two sides had "constructive talks" on trade that included Vice Premier Liu He, U.S. trade representative Robert Lighthizer and Treasury Secretary Steven Mnuchin.

A dramatic escalation of the political unrest in Hong Kong dented investor sentiment further, as local police warned that they were ready to use live bullets if "rioters" continued to use lethal weapons.

"In the short term, trade negotiations and the unrest in Hong Kong are two major factors that suppress the risk appetite across Asia," said Margaret Yang, market analyst at CMC Markets in a note.

Broader Asian peers rallied after the central bank of China, Southeast Asia's biggest trading partner, unexpectedly trimmed a key interbank lending rate on Monday, the first easing in the liquidity tool in more than four years. However, the rate cut failed to lift risk appetite in the Southeast Asian region.

The Philippines index slipped to its lowest in four weeks, with financial services provider GT Capital Holdings shedding over 2.3%, while telecommunication services provider Globe Telecom lost 1%.

Indonesian stocks retreated from previous session's gains, with index heavyweight Telekomunikasi Indonesia accounting for a majority of losses in the benchmark.

The Thai index was flat after data showed that the country's trade-dependent economy grew at its slowest quarterly rate in a year in the third quarter, leading the government to cut this year's growth estimate once again.

Financials were the biggest drags in the index, with Siam Commercial Bank dropping 1.3%.

Bucking the sombre mood, Singapore's index logged in marginal gains even after data implied that the city-state's exports in October shrank for an eighth straight month, missing expectations.

While electronics shipments fell 16.4% in October, the figure could be viewed as showing some tentative signs of stabilization after hitting bottom in June this year, OCBC said in a note.

The Malaysian index traded little changed, while Vietnamese stocks dipped to their lowest since Nov. 1.

(Reporting by Arundhati Dutta; Editing by Sherry Jacob-Phillips)