Story highlights Iraq announces first oil discovery in 30 years

The discovery in Maysan amounts to at least a billion barrels, an official says

Iraq's government depends on oil for 90% of its budget

Iraq's state-owned oil exploration company has made the country's first oil find in 30 years, an Oil Ministry spokesman said Monday.

The company found at least a billion barrels of crude under the ground in a southeastern province near the border with Iran, spokesman Assim Jihad said Monday.

The discovery in Maysan, about 350 kilometers (215 miles) south of Baghdad, is a "significant achievement" for the country, Jihad said.

Despite vast reserves and reliance on oil for government income, exploration in Iraq has been hindered by decades of conflict.

With the world's fourth-largest oil reserves, Iraq's government depends on oil revenues to fund more than 90% of its budget.

JUST WATCHED BP seeks oil contract change in Iraq Replay More Videos ... MUST WATCH BP seeks oil contract change in Iraq 01:32

The discovery comes seven months after exploratory drilling began, Jihad said.

Iraq produces 3.2 million barrels of oil a day, exporting 72% of it, he said.

In 2010, Iraqi officials estimated the country had 143 billion barrels of extractable oil, most of it in the southern oil fields.