In July foreign debt rose partly due to the sale of a billion US dollar sovereign bond, of which 500 million US dollars will be used next month to repay a maturing bond.
In the first half of 2012, the rupee fell sharply to about 130 rupees from around 110 rupees in 2011, partly due to credit spike to finance energy subsidies by the state which was accommodated by the Central Bank.
The share of foreign borrowings in the total state debt has been rising since 2008, when total foreign borrowings fell amid a balance of payments crisis, when hot money fled and the country found it difficult to roll-over maturing commercial loans.
After falling to 40.3 percent of total debt in 2008, the share of foreign debt has risen steadily to 46.9 percent of total debt by June 2012 data from Sri Lanka's public debt office show.
Domestic borrowing had fallen to 53.02 percent from 59.6 percent over the same period.
In July 2012, the share of foreign debt rose to 48.2 percent of total debt and domestic debt fell to 51.7 percent.
Sri Lanka has been borrowing in commercial markets through sovereign bonds and also getting large volumes of money from China's Exim Bank and Development Bank of China.
Most of the Chinese loans however are long-term, with some having tenures as much as 20 years with annual repayments. Commercial loans however are bullet repayments though Sri Lanka has sold 10-year bonds.
Sri Lanka's debt burden measured as a percentage of gross domestic product has fallen from 87.8 percent in 2006 to 78.4 percent in 2011.
Unlike actual debt numbers however GDP is an estimate based on a methodology where state expenses such as salaries are also counted as output.
By June 2012, based on the 6,982 billion rupees GDP in the previous four quarters and total debt of 5,951 billion Sri Lanka's national debt had spiked to 85 percent of GDP.
Sri Lanka's currency however has been strengthening indicating that the rupee value of Sri Lanka's foreign debt may fall by year end.