The Stock Exchange of Thailand jumped more than 1% as most Southeast Asian shares ended higher on Wednesday.
The Philippines rose over 2%, while investors awaited the US Federal Reserve's statement for cues on the pace of future rate hikes after its policy meeting concludes later in the day.
However, resurfacing US-Sino trade tensions after US President Donald Trump announced a 25% tariff on US$200 billion of imported Chinese goods after initially setting them at 10%, weighed on sentiment.
"I think the FOMC will keep to their policy of tightening in 2018. The outlook for 2019 is more uncertain and we will only have more visibility in subsequent meetings when the FOMC updates their economic projections," said Liu Jinshu, director of research at NRA Capital in Singapore.
The SET index gained 1.2%, their seventh rise in nine sessions. The index jumped 20 points, in turnover worth 60.92 billion baht.
Data showed the country's headline consumer price index rose in July.
The annual headline CPI rose 1.46% in July, as expected in a Reuters poll, after a 1.38% jump in June.
Philippine shares were the top gainers among Southeast Asian shares, ending 2.2% higher, their biggest gain in over two months.
Industrials and financials accounted for majority of the gains, while all other sectors ended in the positive territory.
SM Investments Corp gained 4.2% while BDO Unibank ended 3.6% higher.
Indonesian shares ended 1.6% higher, bolstered by financials and industrial stocks, with the index posting its eighth gain in nine sessions.
Fitch Ratings on Tuesday upgraded the Viability Rating of Indonesia's state-owned bank PT Bank Rakyat Indonesia (Persero) Tbk and also reaffirmed the National Ratings on PT Bank Negara Indonesia (Persero) Tbk.
Financials surged, with PT Bank Negara Indonesia (Persero) Tbk rising 5.7% and PT Bank Rakyat Indonesia (Persero) Tbk gaining 3.9%.
Meanwhile, Indonesia's July inflation rate edged up to 3.18% against expectations of a 3.24% rise.
Singapore shares gained 0.3% on the back of financials with DBS Group Holdings, Oversea-Chinese Banking Corp and United Overseas Bank all gaining.
"The banks are going to start reporting their results with DBS reporting tomorrow morning while UOB will report on Friday morning. If we look at their recent share price performance, they have recovered somewhat from the early July lows and hence, we could be seeing some buying ahead of their results," added Jinshu.
Vietnam shares ended lower by 0.4%, with financials and real estate stocks pulling the benchmark down.