Indonesia's rupiah slid to its weakest level in nearly five months on Wednesday as rising US bond yields continued to sap appetite for one of the highest-yielding emerging markets.

Stocks in Jakarta and Kuala Lumpur fell around 1.5%, while neighbouring Manila was down 0.8%, with all three leadings declines across the continent.

Later on Wednesday US President Joe Biden is set to outline how he intends to pay for a $3 trillion to 4 trillion infrastructure plan that could further boost the US recovery versus the world.

"The additional spending boost could further support the US dollar," Mizuho said in a note.

The dollar is on track for its best month since 2016 compared with monthly declines set for many in Asia's emerging currencies, including the rupiah and ringgit.

The International Monetary Fund said strong US growth could help, but may also cause tighter financial conditions and trigger significant outflows from emerging countries.

Indonesia's central bank governor in pre-recorded remarks said the country has ample foreign reserves to ensure the rupiah is stable. He added that Bank Indonesia does not hesitate to intervene in the market to defend the rupiah.

Jakarta's stock market was also set for its worst month since September last year.

In Malaysia, stocks suffered their sharpest fall in nearly three months, falling as much as 1.8%.

The central bank said it expects Malaysia's economic growth in a range of 6% to 7.5% this year, compared with a 5.6% contraction - its worst since the Asian Financial Crisis in 1998 - in 2020.

MSCI's broadest index of Asia-Pacific shares outside of Japan, though up on Wednesday, was on track for its first loss in five months.

China's manufacturing activity expanding at its quickest pace in three months in March did little to support the region.

The yuan, however, edged higher, while Shanghai stocks fell 0.8%.

Singapore stocks also dipped, but are headed for their best month since November.

Eyes will also be on markets in India as COVID-19 cases rise sharply. The rupee weakened to a three week low on Tuesday.