At the end of 2014, the foreign debt in dollar term stood at US$140 billion, a decrease by $1.2 billion from the previous month.
In recent months, the dollar has strengthened against major currencies like Japanese yen and the euro. After conversion to US dollar, loans denominated in non-dollar currencies are of lower value.
"The dollar appreciation reduced foreign debt by $500 million. The foreign debt also dropped by another $700 million in the month mostly by importers' short-term trade payments," the central bank said.
Of total, short-term loans, or those with maturity of less than a year, stood at 40.8 per cent.
Of total, the outstanding foreign debt shouldered by the Thai public sector and the central bank was valued at $22.1 billion and $3.2 billion, respectively.
In December, the central bank's outstanding debt dropped by $100 million from the previous month, as foreign investors continued their net-sell of short-term bonds. In December, the net-sell continued for the fifth month.