The United States on Monday imposed sanctions on the Venezuelan government, a day after President Nicolas Maduro won a controversial election giving his government more power. The sanctions ban any US citizens from doing business with Maduro, and froze Maduro’s assets in their country.

Maduro and his aides claimed 40% of Venezuelans voted in the polls, while Opposition activists said the real figure was only around 12%. The country’s former attorney general, who had quit the job in April, said the vote was fraudulent, The Washington Post reported. Luisa Ortega Díaz also said the government would use its powers to further tighten their monopoly. “How will we control the public budget now? How will we know how much and in what things money is being invested?” she asked.

Steven Mnuchin, US treasury secretary, said, “Yesterday’s illegitimate elections confirm that Maduro is a dictator who disregards the will of the Venezuelan people.” He added that Maduro has become the fourth leader to be blacklisted by the US in such a way – he joins Robert Mugabe, Kim Jong-un, and Bashar al-Assad. Trump’s security adviser HR McMaster said, “Maduro is not just a bad leader. He is now a dictator.”

Fifteen people had died in violence during voting on Sunday. The country faces an even bigger crisis now, after its economy has spiralled and its Opposition appears disorganised. The US is now considering oil sanctions against Venezuela, which could be devastating for the country. Venezuela relies on oil exports for as much as 90% of its revenue.