CARACAS, Venezuela — The Trump administration slapped sweeping financial sanctions on Venezuela on Friday, dramatically ratcheting up tensions between the two countries and making it harder for embattled President Nicolás Maduro to raise badly needed cash to prevent a debt default.

The sanctions, which Trump signed by executive order, prohibit American financial institutions from providing new money to the government or the state oil company, PDVSA. They also restrict the Venezuelan oil giant's U.S. subsidiary, Citgo, from sending dividends back to Venezuela and ban trading in two bonds the government recently issued to circumvent its increasing isolation from Western financial markets.

"Maduro may no longer take advantage of the American financial system to facilitate the wholesale looting of the Venezuelan economy at the expense of the Venezuelan people," Treasury Secretary Steven Mnuchin said at the White House. "These measures will undermine Maduro's ability to pay off political cronies, and regime supporters, and increase pressure on the regime to abandon its disastrous path."

The financial sanctions drew quick rebuke from Venezuela's government, with Foreign Minister Jorge Arreaza calling them the worst aggression against the country in two centuries.

"What do they want — they want to starve the Venezuelan people?" Arreaza told reporters at the United Nations after meeting with Secretary-General António Guterres.

He said his government would fight the measures with all of its diplomatic and economic strength, but also blamed members of the opposition — some of whom expressed satisfaction with the U.S. action — for conspiring to bring further hardships on the Venezuelan economy.

"We are also victims, as he is, of fake news," Arreaza said in a rare show of solidarity with Trump.

A senior Trump administration official said additional sanctions would be imposed if Maduro doesn't reverse course and meet opposition demands that he roll back plans to rewrite the constitution, free dozens of political prisoners, and hold fair and transparent elections.

Maduro has been warning for weeks that the Trump administration was readying a "commercial, oil and financial blockade" in the mold of the one that has punished Cuba for decades.

He found an opportunity to argue his case that he's being unfairly targeted after Trump said earlier this month that he wouldn't rule out a "military option" to resolve Venezuela's crisis.

On Friday, journalists were invited to a shooting range at Caracas' main military base to watch as troops taught a handful of civilian government supporters how to fire assault weapons. The event, attended by military officials from China, Belarus and Russia, was a prelude to military exercises Maduro called for this weekend as a deterrent to any U.S. military intervention.