In Russia, President Vladimir Putin – who signed a mutual defense pact with North Korean leader Kim Jong Un in June – has not denied the reports.

“Russia has never doubted the seriousness of the DPRK in its cooperation, we cooperate with our North Korean friends,” Putin said after hosting a summit of emerging economies.

“What we do is our business,” he said.

The strongman leader then appeared to mock satellite images that purportedly showed North Korean troops on Russian soil.

“Images are a serious thing. If there are images, they must show something.

Putin was speaking hours after lawmakers in Russia’s lower house of parliament voted unanimously to ratify a treaty with North Korea that provides for “mutual assistance” if either side parties were confronted with an attack.

The treaty is expected to be fully ratified by the upper house on November 6.

‘Provocation’

Russia claims to have retaken a series of villages from Ukrainian forces in Kursk, but has failed to push the Ukrainians out of its territory.

Putin claimed Thursday that Moscow’s forces were “advancing” there and had blocked “Ukrainian units invading the Kursk region.”

Russia, under massive international sanctions, has significantly warmed ties with isolated Pyongyang since sending troops to Ukraine.

South Korea said Thursday that the presence of North Korean troops in Europe would mark a major escalation for global security.

President Yoon Suk Yeol called the deployment “a provocation that threatens global security beyond the Korean Peninsula and Europe” after talks with Polish President Andrzej Duda.

South Korea, one of the world’s top ten arms exporters, has long resisted calls from its allies, including Washington, to supply weapons to kyiv.

But he suggested he might review the policy in light of North Korea’s actions, and Yoon said Thursday that Seoul would “take necessary measures in cooperation with the international community” to respond.

South Korea plans to send weapons

A South Korean official in the president’s office said this week that Seoul would “support (Ukraine) with defensive weapons and if things go off the rails, we may consider sending offensive weapons.”

Seoul has already sold billions of dollars worth of tanks, howitzers, attack aircraft and rocket launchers to Poland, a key ally of kyiv.

In June, South Korea agreed to transfer knowledge needed to build K2 tanks to Poland, and experts said this could be a key step toward production in Ukraine.

Yoon announced that South Korea and Poland would sign an agreement on a second contract for South Korean K2 tanks by the end of the year.

Duda was on a four-day visit to South Korea that ends Friday with a stop at Hyundai Rotem, producer of the K2 tanks, and Hanwha Aerospace, South Korea’s largest defense contractor.

Hanwha Aerospace has signed a $US1.64 billion ($2.73 billion) deal with Poland for the supply of rocket artillery units.

Before the meeting between Yoon and Duda, a North Korean balloon carrying trash landed at the presidential complex in Seoul.

Korean media reported that it contained propaganda leaflets ridiculing the South Korean president and his wife.