An olive green North Korean train, bearing a gold stripe, crossed the border into Russia on Tuesday, carrying Kim Jong Un for a meeting with President Vladimir Putin. This is Kim’s first visit to a foreign country in over four years. The visit is warned by the US to exercise caution over potential arms agreements between North Korea and Russia. The visit includes negotiations between delegations and potential one-on-one communication between the leaders. Kim’s private train is equipped with high-level security features, such as bulletproof windows, reinforced walls and floors, and even attack weapons and a helicopter for emergency escape. The heavy train travels at a slower speed of 60 kilometres per hour, but it offers more flexibility and protection compared to an aircraft. The train is accompanied by two other trains for added security. Kim’s armored train has been used in the past for meetings with Putin, Chinese President Xi Jinping, and former US President Donald Trump. However, Kim occasionally opts for air travel, especially during his teenage years when he frequently traveled by air while studying in Switzerland. The meeting between Kim Jong Un and Vladimir Putin signifies an important diplomatic development in the region.