The United Nations' top official for Libya on Monday called for lifting the production blockade at two oil fields including the country’s largest, as oil prices soared to over $130 a barrel.

Stephanie Williams, the U.N. special adviser on Libya, said blocking oil production from the Sharara and el-Feel fields "deprives all Libyans from their major source of revenue."

"The oil blockade should be lifted," she said on Twitter.

The closures have caused Libya’s daily production of oil to drop by 330,000 barrels, according to the state-run National Oil Corporation.

Before the shutdown, Libya’s production of oil was at around 1.2 billion barrels per day (bpd). The North African nation has the ninth-largest known oil reserves in the world, and the biggest oil reserves in Africa.

The closure cost Libya more than $34.6 million per day in lost revenues, the NOC said.

Company head Mustafa Sanallah blamed the shutdown on an armed group, led by Mohamed Bashir al-Garg, in the mountainous town of Zintan, around 136 kilometers (over 84 miles) southwest of the capital, Tripoli.

Al-Garg, who also commands a force guarding oil facilities in the area, said the closures were due to "dire living conditions," demanding authorities provide services to people in the region, according to local media.

The shutdown came as Brent crude, the international pricing standard, hit $139.13 per barrel before falling back Monday to be traded at $130.29 a barrel.

The growing increase of oil prices is a consequence of the Russian invasion of Ukriane, which sent shockwaves to the world markets.