CARACAS, Venezuela -- A senior U.S. diplomat was holding talks with Venezuela's hostile government and its opposition on Wednesday, apparently hoping to prevent a humanitarian disaster and ease a political crisis in the deeply polarized nation.

Thomas Shannon, the U.S. undersecretary of state for political affairs, met Tuesday with several leading opposition figures. Government-backed news media said he was expected to meet Wednesday with President Nicolas Maduro, one of the world's most vociferous critics of the United States.

With Venezuela facing an economic crisis that has led to food riots and aggravated political unrest, U.S. officials has said they want to avoid bloodshed and a humanitarian crisis that might spill across its borders, undermining President Barack Obama's legacy in a region where he made history by reopening relations with Cuba.

Neither U.S. nor Venezuelan officials gave immediate reports on the content of the discussions.

The United States has criticized Maduro's government for jailing critics and blocking the opposition-controlled Congress as part of attempts to squelch unrest caused by growing shortages of food and many other key goods, as well as triple-digit inflation.

The U.S. also is backing a scheduled Thursday session of the Organization of American States where regional governments will debate a proposed diplomatic intervention to ease tensions -- a measure opposed by Maduro.

The opposition is pushing for a recall referendum this year to cut short Maduro's term and trigger new elections. They say the national electoral council and courts are stacked in the government's favour and are trying to delay or kill the recall move.

The visit fits with the Obama doctrine of holding talks with adversaries, according to Michael McCarthy, a fellow at American University's Center for Latin American & Latino Studies.

The administration may be trying to take advantage of the post Cuba-normalization era in which Latin American leaders are more receptive to outreach from Washington.