The outgoing UK leader created an arch of sunflowers — Ukraine's national flower — outside his Downing Street office to commemorate the eastern European nation's independence day on Wednesday. The gesture also comes as Ukraine prepares to mark six months since the Russian invasion began on February 24.

"We will never recognize Russia's annexation of Crimea or any other Ukrainian territory," Johnson said in a video address to an international summit on the Crimean Peninsula, which Russia seized in 2014.

"In the face of (Russian President Vladimir) Putin's assault we must continue to give our Ukrainian friends all the military, humanitarian, economic and diplomatic support that they need," Johnson said.

Johnson has been steadfast in his support for Ukraine since the invasion began. The prime minister, who will step down early next month, sought to deflect from scandals and criticism at home by positioning himself as the leader of the international effort to help Ukraine combat Russian aggression.

Since the Russian invasion began, Johnson has pledged 2.3 billion pounds (USD 2.8 billion) of military aid to Ukraine, including armoured vehicles and anti-tank missiles. He has also dispatched economic support, guaranteeing millions in World Bank loans for the country.?