South Korea's spy agency says that North Korea has recently supplied additional artillery systems to Russia to support its war efforts against Ukraine.

The number of North Korean troops stationed inside Russia could grow to 100,000, Ukrainian President Volodymyr Zelenskiy said on Tuesday. Kyiv and its Western allies say North Korea has supplied Russia with weaponry and troops to bolster its full-scale invasion of Ukraine.

North Korean leader Kim Jong Un met with the leader of a Russian delegation in Pyongyang and called for deepening trade, economic and scientific ties between the two countries, state media reported Tuesday.

Markets sold off Tuesday as geopolitical tensions escalated between Ukraine and Russia. The Dow fell 300 points, or 0.7%; and the S&P 500 and Nasdaq 100 both moved around 0.5% lower. The selling comes after Moscow changed its nuclear doctrine following the Biden administration giving Ukraine permission to use longer-range weapons inside targets in Russia.

European equities declined for a third day, with the benchmark hitting the lowest level in more than three months amid concerns about an escalation of Russia’s war in Ukraine.

Oil prices edged up on Monday after fighting between Russia and Ukraine intensified over the weekend, although concerns about fuel demand in China, the world's second-largest consumer, and forecasts of a global oil surplus weighed on markets.