The Taiwan unit climbed 0.3 percent against the dollar, and the Philippine peso rose 0.2 percent as market players added short positions to the greenback.
Most emerging Asian currencies had edged higher on Tuesday as investors covered short positions built up on fears the summit that opens on Thursday would not produce progress in tackling Europe's debt crisis.
Although some regional units extended gains on Wednesday, trading was light. Market players said already-low hopes for the summit were further cut after German Chancellor Angela Merkel said common euro-zone bonds would not happen as long as she lives.
"Pricing in some disappointment actually suggests more reasonable expectations, which should be positive once dollar strength takes a breather," said Andy Ji, Asian currency strategist for Commonwealth Bank of Australia in Singapore.
"We could see a pullback from being oversold in the Asia ex-Japan space, so there will be a short window of opportunity to go long Asia ex-Japan in the coming week," he said.
TAIWAN DOLLAR
US dollar/Taiwan dollar slid as the island's exporters sold it for month-end settlements.
Taiwanese insurers also unloaded US dollars in spot and non-deliverable forwards (NDFs) markets to hedge their overseas investments, dealers said.
But some foreign financial investors bought the pair, limiting its downside.
WON
Dollar/won fell on exporters' offers for month-end settlements, while offshore covered short positions in the pair.
Local energy importers bought dollars on dips, capping the won's strength, dealers said.
"The market stayed heavy with exporters' deals. But risk-off sentiment also remained strong and players absorbed all of the exporters' dollar offers," said a local bank dealer in Seoul.
SINGAPORE DOLLAR
US dollar/Singapore dollar rose, but gave up some of its initial gains on selling by some hedge funds and a firm yuan fix.
But the overall market was tepid, with investors willing to stay in a range between 1.2750-1.2800 for the rest of the session.