At the start of the week, the U.S. President Donald Trump shockingly punctured optimism around trade talks between the world's top two economies by threatening to hike import tariffs on Chinese goods from Friday.

Short positions on the Chinese yuan were at their highest since mid-December, a fortnightly poll of 12 participants showed.

In the previous poll, bullish bets on the yuan were seen edging higher on expectations the central bank could put any broader policy easing measures on hold after hints of a recent recovery in China's economy.

Market participants continued to be bearish on the South Korean won as a slew of weak domestic economic data weighed on the unit.

Short positions on the won, the worst performing Asian currency this year, were at their highest since January 2016. Risk appetite was also hurt by a missile test by North Korea earlier in the week.

Data released late last month showed South Korea's economy unexpectedly shrank in the first quarter, marking its worst performance since the global financial crisis, while April exports also contracted.

Meanwhile, short bets on the Taiwan dollar climbed to their highest since February end.

Like South Korea, Taiwan's economy also relies heavily on its technology-oriented exports, and has seen economic headwinds due to a slowdown in demand for the like.

Most Asian currencies are also under the pump with factory activity in the continent still appeared to be on shaky ground as global demand remained subdued and China's stimulus measures were yet to show their full pulling power.

Investors turned more bearish on the Malaysian ringgit too, with the short bets rising to their highest since mid-December.

Earlier this week, Malaysia's central bank became the first in Southeast Asia to cut its key interest rate this year. Bearish positions on the Thai baht also rose, to their highest level since late November.

The Thailand central bank on Wednesday kept its benchmark rate where it has been since December, as expected, while the long-delayed results of the country's first election since a 2014 military coup produced no clear winner. The election results came in after the close of this poll.

Bets on the Indonesian rupiah and the Singapore dollar turned bearish for the first time since mid- March and mid-December, respectively.

While long bets on the Indian rupee remained so for a fifth straight poll, they weakened slightly from two weeks back.

Investors now await the results of India's general elections on May 23, amid expectations that Prime Minister Narendra Modi's ruling Bharatiya Janata Party would retain power.

The Reuters survey is focused on what analysts believe are the current market positions in nine Asian emerging market currencies: the Chinese yuan, South Korean won, Singapore dollar, Indonesian rupiah, Taiwan dollar, Indian rupee, Philippine peso, Malaysian ringgit and the Thai baht.

The poll uses estimates of net long or short positions on a scale of minus 3 to plus 3.