The White House has ordered the U.S. military to focus almost exclusively on enforcing a "quarantine" of Venezuelan oil for at least the next two months, Reuters reported on Wednesday, citing a U.S. official.

"While military options still exist, the focus is to first use economic pressure by enforcing sanctions to reach the outcome the White House is looking (for)," the official said.

"The efforts so far have put tremendous pressure on (Venezuelan President Nicolas) Maduro, and the belief is that by late January Venezuela will be facing an economic calamity unless it agrees to make significant concessions to the U.S.," said the official, speaking on condition of anonymity.

Bella I, the third oil tanker pursued by U.S. forces, has turned away from its route to Venezuela to load cargo and retreated into the Atlantic Ocean, according to U.S. media reports.

U.S. President Donald Trump ordered a "full and total blockade" of all sanctioned tankers entering or leaving Venezuela last week, announcing Maduro's government as a U.S.-designated foreign terrorist organization.

Venezuela has repeatedly accused Washington of seeking regime change and military expansion in Latin America, condemning the interception of oil tankers as "piracy."

Asked if the goal was to force Maduro from power, Trump told reporters on Monday that it would be "smart" for Maduro to step down. "If he plays tough, it'll be the last time he's ever able to play tough," he added.

The UN Security Council on Tuesday held an emergency meeting on the situation in Venezuela, at which the overwhelming majority of Security Council members called for respect for the UN Charter and restraint to avoid further escalation.