North Korean leader Kim Jong Un has sent a letter congratulating the Queen as the UK began a four-day celebration marking her 70 years on the throne.

North Korea’s Foreign Ministry said on its website that Mr Kim sent a letter congratulating the Queen and the British people.

North Korea and Britain established diplomatic relations in 2000 and have maintained embassies in each other’s capitals despite a steady decline in bilateral ties.

North Korea’s relations with the West have worsened in recent years as it accelerated its nuclear weapons and missile development in a push to acquire an arsenal that could threaten the United States and its allies in Asia.

North Korea has criticised Britain in recent years for supporting international sanctions against the country over its nuclear ambitions and human rights record, and for participating in a new US-led alliance to help Australia acquire nuclear-powered submarines.