The United States on Friday joined the European Union in imposing sanctions on Russian President Vladimir Putin, the latest in a series of punitive measures taken in response to Moscow's invasion of Ukraine.It is rare to impose sanctions on a head of state. Russian Foreign Minister Sergey Lavrov and members of the country's national security team were also slapped with sanctions."The president of the Russian Federation has perpetrated horrific aggression against Ukraine," the Treasury Department said in a press release as it announced the sanctions that will lead those listed to face asset …READ FULL ARTICLE