The United States military has captured a seventh oil tanker linked to Venezuela as part of the Trump administration’s escalating efforts to tighten control over the country’s oil exports and enforce a naval quarantine of sanctioned vessels, military officials said.

A day after she gave President Donald Trump her Nobel Peace Prize medal, Venezuelan opposition leader María Corina Machado insisted that her country was on an irreversible path toward democracy, even as Trump has spoken far more frequently in recent days about securing Venezuelan oil than bringing about free elections.