North Korea must "push ahead with the work for exponentially boosting the production of nuclear weapons and diversifying the nuclear strike means," said Kim Jong Un.
Kim inspected a Russian fighter jet factory that is under Western sanctions, nuclear-capable strategic bombers, hypersonic missiles and warships last week.
North Korean leader Kim Jong Un inspected Russian nuclear-capable strategic bombers, hypersonic missiles, and warships accompanied by Russian Defense Minister Sergei Shoigu.
Kim was briefed on technical details about Russian space vehicles during his visit to a cosmodrome, but there was no mention of any arms supplies, trade of weapons or technical assistance.
Beijing and Moscow have called for sanctions to be eased on the North to jumpstart diplomatic talks and improve the humanitarian situation.
When asked by reporters if Russia would help Kim build satellites, Putin replied: "That's why we came here."
The North Korean leader has now arrived in Russia for his meeting with Putin.
Russia's President Vladimir Putin and North Korea's leader Kim Jong Un may talk about Moscow sending humanitarian aid to Pyongyang.
The United States has said it would be a "huge mistake" for North Korea to supply Russia with weapons to use in Ukraine and warned Pyongyang would "pay a price".
Submarine No. 841 - named Hero Kim Kun Ok after a North Korean historical figure - will be one of the main "underwater offensive means of the naval force" of North Korea, leader Kim Jong Un said.