The Stock Exchange of Thailand closed slightly here, while other Southeast Asian markets ended mixed as investors' risk appetite soured on fears of more trade protectionist measures from the United States.
US President Donald Trump said on Friday he was ready to impose tariffs on all US$500 billion of imported goods from China, threatening to escalate a clash over trade policy that has unnerved financial markets.
The dollar declined against major currencies after Trump criticised the Federal Reserve's monetary tightening policy.
"Market players will likely closely monitor China's policy reaction, especially on the RMB front in the interim. Asian markets are likely to also trade with a cautious tone today," OCBC said in a note.
The SET index earned 4.69 points or 0.28% to close at 1,675.75, in turnover of 49 billion baht.
Singapore shares were down after four straight sessions of gains ahead of June inflation data.
The annual headline inflation rate is expected to have risen in June from the previous month, according to a Reuters poll.
Financials were among the biggest drag with index heavyweights DBS Group Holdings, Oversea-Chinese Banking Corp and United Overseas Bank shedding between 0.9% and 1%.
Indonesian shares rose 0.9% with all sectors but materials in positive territory.
Financials led the charge, with Bank Central Asia Tbk PT rising 1.7% to its highest in more than three months, while Bank Mandiri (Persero) Tbk PT gained nearly 2%.
The impact of US-China trade tensions on Indonesia is "not a lot" as exports to these countries are not the biggest parts of Indonesia's economy, said Nomura Indonesia analyst Elvira Tjandrawinata.
"Indonesia is instead affected through the impact global events have on the local currency, which pours into general sentiment in the economy," she said.
Last week, the Indonesian central bank kept its benchmark interest rate unchanged as expected, taking a pause in its monetary tightening cycle.
Vietnam shares jumped 1.4%, driven by gains in real estate and financial stocks. Vingroup JSC and Petrovietnam Gas Joint Stock Corp were the top gainers.