Angola is hoping to get a $1 billion credit line from the World Bank and borrow billions more from China, the sources said.
The continent's second largest crude exporter is battling with falling oil prices.
The decision comes after a drop in oil prices prompted the Finance Ministry to cut proposed 2015 budget spending by $17 billion after slashing expected oil revenues.
The revised budget figures was based on an oil price of $40 per barrel rather than the $81 previously forecast.
The revised plan forecasts a budget deficit of 7 percent of GDP.
The shortfall could be partially covered by Angola's $26 billion in foreign exchange reserves.
Planning Minister Job Graca told Angola News Agency early February that he expects the economy to grow 6.6 percent this year with the oil sector expanding 9.8 percent, while inflation should average 7-9 percent.
Some economists think Angola is being too optimistic and project economic growth closer to 3 percent, down from 4 percent last year and a peak of 12 percent in 2012.
Oil accounts for around half of Angola's GDP, 80 percent of tax revenues and 90 percent of export earnings.
An almost halving of oil prices in the last six months will result in a current account deficit of 19 percent of GDP, the first time Angola has posted a deficit since 2009, the central bank said.