Dollar drops against dong

Vietcombank sold the greenback at VND26,368, down 0.05% over the weekend. On the black market, the currency went up 0.12% to around VND26,447.

The State Bank of Vietnam lowered its reference rate by 0.05% to VND25,113.

Globally, Japan's yen surged on Monday, dragging down the dollar across markets as rate checks have investors on high alert over the risks of the first joint U.S.-Japan currency intervention in 15 years, Reuters reported.

The U.S. dollar index, which measures the greenback's strength against a basket of six currencies, was down 0.1% at 97.082, nearing a four-month low.

The yen rose as much as 1.2% to 153.89 per dollar, its strongest since November. The euro made a four-month high of $1.1898 and was last up 0.4% at $1.18665.

Sterling was 0.1% higher at $1.36615, while the Aussie advanced 0.3% to $0.69165 and the kiwi rose 0.2% to $0.59605.

"The dollar has been fragile anyway, but the gain in the yen has been the precipitating trigger for the market to sell it across the board," said Marc Chandler, chief market strategist at Bannockburn Capital Markets in New York.