The law still must be approved in a national referendum that has been scheduled for April 22.
The Kremlin has made military modernization its top priority.
The resignation raises deep questions about the long-term shape of Russia's political system and the future of Putin.
The odd invitation reportedly came during a meeting at the Kremlin between the Vietnam veteran and the former KGB officer.
North Korea's leader Kim Jong-Un will visit Russia for talks with Vladimir Putin this month, the Kremlin said Thursday.
Putin said that Russia plans to dramatically increase cargo shipments across the Arctic sea route.
Putin suspended Russia's participation in a nuclear arms treaty the Trump administration already decided to leave.
Putin said Russia will retaliate by fielding new weapons that will take just as little time to reach their targets.
Secretary of State Mike Pompeo witnessed NATO live-fire exercises in a sign to Warsaw that the U.S. has its eye on Russia.
Vladimir Putin has accused the U.S. and the West of destabilizing the Balkans with NATO expansionist policies.