Most Asian currencies weakened on Monday as risk appetite in the region was dented further, with heightened tensions between the United States and Iran sending crude oil and safe-haven gold prices higher.
The US and Iran are locked in a war of words, exchanging threats of attacks on each other and stoking concerns of an extended conflict, after a top Iranian military commander was killed in Iraq by an American drone strike on Friday.
Oil prices have surged more than 2%, sending Brent futures above the $70 per barrel mark, following a 3% rise on Friday, after the killing of the Iranian commander Qassem Soleimani and the ensuing rise in tensions.
"The Middle East tensions have led Brent crude prices towards $70/bbl, up from just above $60 a month ago... The last thing markets want is a move from a tit-for-tat (Sino-US) tariff war to sabre-rattling in the Gulf," said DBS Group Research analysts in a note.
The currencies of India and Indonesia - two major Asian economies exposed to the impact of oil imports on their current account deficit - wilted under pressure.
The Indian rupee weakened as much as 0.4% to its worst level in more than seven weeks, while the Indonesian rupiah fell about 0.3% to a one-week low of 13,920 against the dollar.
Also, Indonesia's central bank intervened in the spot currency, domestic non-deliverable forward (DNDF) and bond markets to stabilise movements, the head of its monetary management, told Reuters.
"The key question is whether the oil market would be able to absorb any potential supply losses, and the simple answer is that it will obviously depend on the scale of any disruptions," ING analysts wrote in a note.
The Malaysian ringgit, the Philippine peso and the Korean won weakened about 0.2% each, while the Singapore dollar fell slightly.
The weakness in the Chinese yuan was relatively marginal - a drop of about 0.1% -even as investors await more concrete details of the first phase of the Sino-US trade deal, scheduled for mid-month. Meanwhile, the Taiwan dollar and the Thai baht strengthened marginally.