India, Jan. 7 -- The United States has carried out a dramatic high-seas operation to take control of a Russian-flagged oil tanker in the North Atlantic, marking a sharp escalation in Washington's campaign against sanctioned oil shipments linked to Venezuela. The seizure followed weeks of surveillance, pursuit, and growing diplomatic friction with Moscow, officials confirmed on Wednesday.

U.S. authorities secured the vessel after an extended chase that began off the coast of Venezuela last month. The Department of Homeland Security led the operation with support from the U.S. military, signaling a coordinated enforcement push against what Washington calls illegal oil trafficking networks.

The tanker, now named Marinera, previously operat...