Russian President Vladimir Putin’s visit to North Korea is cause for great concern, the US government said on Tuesday. “The deepening cooperation between Russia and the DPRK is something that should be of concern,” US Department of Defence spokesman Pat Ryder said in Washington, using the acronym of the Democratic People’s Republic of Korea. “Especially to anyone that’s interested in maintaining peace and stability on the Korean peninsula, but also supporting the people of Ukraine as they continue to fight against Russian aggression,” Ryder continued. White House spokeswoman Karine Jean-Pierre…