Venezuelans await president's return as oil-fueled revolution teeters on the edge

Venezuelan President Nicolas Maduro has made an urgent tour to seven nations as he seeks support for his teetering oil-dependent economy.

The government said Friday Maduro had stopped in Portugal. It was unclear when he would return to Venezuela, where shortages have become more severe and political opponents are calling for new protests.

Falling oil prices have strangled Venezuela's main source of foreign revenue. Analysts say the combination of economic, political and social troubles is creating the country's worst crisis since the start of Hugo Chavez's socialist revolution in 1999.

Maduro has sought financial support abroad and has urged OPEC to take action to stop oil's decline. While there is no indication OPEC intends to curtail output, Maduro says investments from China and elsewhere will help Venezuela avoid economic catastrophe.