Russian President Vladimir Putin and North Korean leader Kim Jong-un signed a "comprehensive strategic partnership" treaty at a summit in Pyongyang on Wednesday (Korea time) amid concerns about the security implications of their military ties. The department spokesperson said this.

“Deepening cooperation between Russia and the DPRK is a trend that anyone interested in maintaining peace and stability on the Korean Peninsula, upholding the global nonproliferation regime, adhering to UN Security Council resolutions, and supporting the people "should be a matter of great concern." Ukraine is defending its freedoms and independence against Russia’s brutal aggression,” the spokesperson told Yonhap news agency via email.

"As we have said before, we do not think any country should give Mr. Putin the platform to promote a war of aggression against Ukraine," the official said.

The spokesperson also stressed that Russia is “blatantly violating the UN Charter and working to undermine the international order.,

"We cannot turn a blind eye to Russia's clear violations of international law in Ukraine," the spokesperson said, Yonhap news agency reported.

A Pentagon official responded cautiously, saying he was aware of reports of a summit between Putin and Kim.

"We have seen the reports and will continue to monitor the situation," the official said in response to a question from Yonhap news agency. "We don't have anything else to give right now."

The Pyongyang summit came amid deep concerns that military cooperation between Pyongyang and Moscow would help boost Russia's war efforts in Ukraine and advance North Korea's weapons programs to the detriment of regional and global security.