He provided the documents on condition of anonymity to protect himself from possible reprisals from Vietnam's authoritarian government. Vietnam's Ministry of Industry, the Vietnam Oil and Gas Group, known as Petrovietnam or PVN, and the Foreign Ministry did not respond to multiple emails seeking comment on the payment scheme. Last Friday, Britain announced a new set of sanctions targeting Russia's oil revenues and military supplies, including banning 70 ships from a "shadow fleet" it said is being used to transport Russian oil to circumvent international sanctions. And since Washington lifted its arms embargo on Vietnam in 2016, it has become increasingly important in supplying defense goods. In 2011, Russia extended Vietnam $2 billion in credit for a deal that included two frigates for its navy and 64 T90S tanks.