The State Bank of Vietnam has asked credit institutions to provide reports concerning outstanding loans and investments that involve US dollars.
The State Bank is requesting the information so that the institution can begin drafting a monetary policy for the latter months of the year.
Lenders were also told to draw up plans concerning how they will use their foreign currency reserves to pay debt during this year's final quarter and next year's first quarter.
The report must be completed and delivered to the State Bank this Friday.
By the end of September, total outstanding loans in foreign currencies at banks in Ho Chi Minh City were VND186.1 trillion (US$9.5 billion), up 36 per cent against the same period last year.
The US dollar credit growth during September increased by 6.1 percent against August, while the month-on-month dollar credit growth in August was up just 1 percent against July.
In an unusual move, loans in foreign currencies exceeded mobilized capital. Financial experts explained that banks had a surplus of US dollars that they received from mother companies or foreign credit institutions.
This is the second time the central bank has asked for such reports.
In May, commercial banks and financial companies were ordered to provide a detailed report about their foreign exchange operations to help reduce the country's trade deficit and improve Vietnam's payment balance.