Russian President Vladimir Putin said on Thursday that Russia could supply weapons to North Korea in a retaliatory move to Ukraine by Western countries.

Putin was speaking to reporters in Vietnam a day after visiting nuclear-armed North Korea and signing a mutual defence agreement with its leader Kim Jong Un.

Western countries view North Korea as an outcast state as it has developed nuclear and ballistic missiles in defiance of UN sanctions, and they also view with concern growing ties between Moscow and Pyongyang.

Putin threatened earlier this month that Russia could arm Western rivals because the West was supplying Ukraine with high-precision weapons and allowing it to fire them at targets inside Russia.

In his latest remarks, he said North Korea could be one such recipient of Russian weapons.

“I said, including to Pyongyang, that we reserve the right to supply weapons to other regions of the world. Taking into account our agreements with (North Korea), I do not exclude that either,” he said.

Under the treaty signed by Putin and Kim on Wednesday, the two sides commit to providing immediate military assistance to each other in the event of an armed aggression against either one.

Putin said Moscow hopes its cooperation with North Korea will serve as a deterrent to the West, but there is no need to use North Korean troops for the war in Ukraine.

“Regarding the possibility of somehow using each other’s capabilities in the conflict in Ukraine, we are not asking anyone for this, no one has offered it to us, so there is no need for it,” he said.

The United States and Ukraine say North Korea has already supplied Russia with large quantities of artillery and ballistic missiles, a claim Moscow and Pyongyang deny.

South Korea, nuclear doctrine

Putin said South Korea would make a “big mistake” if it decided to supply arms to Ukraine and that Moscow would respond to the move in a way that would be painful for Seoul.

He spoke after South Korean news agency Yonhap said Seoul would review the possibility of supplying arms to Ukraine in light of the mutual defence agreement signed by Putin and Kim a day earlier.

Putin also elaborated on comments he made earlier this month about nuclear weapons, saying Moscow was thinking about possible changes to its doctrine regarding their use.

Putin said this was because of changing views on nuclear use among Russia’s adversaries.

Russia’s current doctrine states that it may use nuclear weapons in response to a nuclear attack or in the event of a conventional attack that poses an existential threat to the state.

Since the war in Ukraine began, some Russian military analysts have been advocating that Moscow should reconsider its stance and even launch some kind of nuclear strike to “calm down” its opponents in the West.

Putin told reporters that Russia was thinking about changing its doctrine as its potential adversaries were working on “new elements” related to lowering the threshold for nuclear use.

“In particular, extremely low-yield explosive nuclear devices are being developed. And we know that there are considerations in expert circles in the West about the possibility of using such means of destruction,” he said.

Putin said there was “nothing particularly terrible” about it, but Russia needed to pay attention to it.

Since launching his full-scale invasion of Ukraine in February 2022, which he sees as a special military operation to ensure Russia’s own security, Putin has frequently talked about the size and power of Russia’s nuclear arsenal and warned the West of the risk of a global conflict if it escalates further into war.