Russian lawmakers on Thursday ratified a pact with North Korea envisioning mutual military assistance, a move that comes as the US confirmed the deployment of 3,000 North Korean troops to Russia. The lower house of the Russian parliament, the State Duma, voted quickly to endorse the “comprehensive strategic partnership” treaty that Russia’s President Vladimir Putin signed with North Korean leader King Jong Un on a visit to Pyongyang in June. The upper house is expected to follow suit soon.

The pact obliges Russia and North Korea to immediately provide military assistance using “all means” if either is attacked. It marked the strongest link between Moscow and Pyongyang since the end of the Cold War. Russia and North Korea have previously rejected assertions by the US and its allies that Pyongyang has given Moscow ballistic missiles and millions of artillery shells for use in Ukraine.