The world's big economies have hit Russia with a wall of sanctions after its invasion of Ukraine.

Russian President Vladimir Putin said on Saturday the sanctions imposed on his country were akin to a declaration of war.

Following is a roundup of some of the broadest measures taken against Putin and those around him, and on key sectors of the Russian economy.

PUTIN & OFFICIALS

The United States, European Union, Britain and Canada have frozen the assets of Putin and Foreign Minister Sergei Lavrov. Washington has imposed a travel ban on the two, but the EU has not, in order to facilitate negotiations with them if the opportunity arises.

The EU has also sanctioned Dmitry Grigorenko, the deputy prime minister, Kremlin press secretary Dmitry Peskov and other Russian officials.

Putin is now one of only three world leaders blacklisted by the EU, along with Syria's Bashar al-Assad and Alexander Lukashenko of Belarus.

TYCOONS BLACKLISTED

The United States, EU and Britain have blacklisted a growing number of leading Russian businessmen such as metals and technology tycoon Alisher Usmanov; Igor Sechin, the chief executive of Russia's biggest oil producer Rosneft; Nikolai Tokarev, the head of oil producer Transneft.

The EU has sanctioned business figures including Mikhail Fridman, the co-founder of Alfa Group, which owns Russia's largest privately owned bank Alfa-Bank; Fridman's business partner Petr Aven; Alexei Mordashov, Russia's richest man and the owner of major steelmaker Severstal.

Britain will on Monday introduce legislation designed to allow ministers to tighten restrictions on Russian businesses and wealthy Russian individuals.

Italian police seized villas and yachts worth 143 million euros ($156 million) from five high-profile Russians, the government said on Saturday.

Canada has said the holdings of all Russian oligarchs and companies in the country are under review.

Australia has imposed sanctions on Russia targeting several of its elite citizens and lawmakers.

CENTRAL BANK & RUSSIAN FINANCIAL SYSTEM

The United States, EU, Britain, Switzerland, Japan, Canada and others have banned transactions with Russia's central bank, finance ministry and sovereign wealth fund. They have also moved to freeze the overseas assets of all three entities.

SWIFT KICKS RUSSIAN BANKS OUT

Seven Russian banks have been excluded from the SWIFT messaging system that underpins global transactions.

The banks are Russia's second-largest lender VTB, along with Bank Otrkitie, Novikombank, Promsvyazbank, Bank Rossiya, Sovcombank and VEB.

Sberbank, Russia's largest lender, and Gazprombank have not been included as they are the main channels for payments for Russian oil and gas, which EU countries are still buying for now. Sberbank said last Wednesday it was exiting almost all European markets.

Visa, Mastercard, American Express, PayPal and others have blocked Russian banks from using their networks.

NORD STREAM 2 EXPECTED TO WIND DOWN

Nord Stream 2, a recently completed pipeline from Russia to Germany, was awaiting regulatory approval by EU and German authorities before Berlin put its certification on ice following the invasion.

The German unit of the Gazprom-led pipeline said last Thursday it would probably be wound up after Berlin halted certification.

Washington has imposed sanctions on the company in charge of building the pipeline.

AIRLINES SHUT RUSSIAN AIRSPACE

The EU, United States, Canada and Britain have shut their airspace to Russia, banning all Russian aircraft from taking off, landing or overflying their territory.

The EU has banned the export, sale, supply or transfer of all aircraft, aircraft parts and equipment to Russia.

DEFENSE & TECH SECTORS

The United States and EU already have sanctions in place on Russia's energy and defense sectors, with state-owned gas company Gazprom, its oil arm Gazpromneft and oil producers Lukoil, Rosneft and Surgutneftegaz facing various types of curbs on exports/imports and debt-raising.

Washington is implementing export controls that will restrict Russian access to semiconductors, computers, telecommunications, information security equipment, lasers, and sensors needed to sustain its military capabilities.

Similar measures were deployed during the Cold War, when sanctions kept the Soviet Union technologically backward and crimped economic growth.

The EU has toughened its existing sanctions on goods that can be used for civilian or military purposes, targeting the military-industrial complex of Russia and Belarus and limiting their access to advanced technology such as drones and software for drones, software for encryption devices, semiconductors and advanced electronics.

Other countries have imposed similar export controls including Singapore, Japan and Switzerland.