Venezuelan leader Nicolás Maduro says escalating pressure from the US comes down to one thing: Washington wants to grab the South American nation's vast oil reserves.

The Trump administration’s seizure of an oil tanker off the coast of Venezuela is one of the most dramatic twists yet in a military pressure campaign against Venezuelan dictator Nicolás Maduro.

Venezuelan authorities said the U.S. government had unilaterally suspended a scheduled deportation flight that was due to land on December 12. The claim came in a statement issued by Venezuela’s Ministry of Justice on Thursday, which accused the U.S. of disrupting a process that had previously been agreed upon.

Venezuela is bracing for a possible land attack after President Donald Trump said, “It’s going to be starting on land pretty soon,” following the U.S. seizure of an oil tanker.

President Trump’s secretary of state and national security adviser has long sought to cripple or topple Cuba’s government, which has close security and economic ties to Venezuela.

Venezuela’s foreign affairs minister denounced the seizure, calling it a “blatant theft” and “an act of international piracy.”

Experts say that Russian and Chinese support for Venezuela has largely dried up, with no prospect of real military or financial aid.

Venezuelan opposition leader Maria Corina Machado on Friday promised political change after slipping out of the country in secret to collect the Nobel Peace Prize, as the shock waves intensified from the Trump administration's seizure of an oil tanker earlier this week.