When Russia began its invasion of Ukraine in the early hours of 24 February, the first foreign leader Ukrainian President Volodymyr Zelenskyy called was Britain's Boris Johnson.
Asked why the UK prime minister was number one on the list, the president's top security official told Sky News: "They are friends. Britain is our friend."
Oleksiy Danilov has been by Mr Zelenskyy's side in the capital Kyiv for the past eight weeks of war as Secretary of the National Security and Defence Council of Ukraine.
He revealed how he had spoken to his boss at the start of Russia's offensive - aimed at toppling Ukraine's government - about the risk of remaining in Kyiv, saying the advice from western intelligence agencies had been for the president to leave.
"He told me: 'I will not go. What happens will happen. We will fight'… You need to be brave to say those words in that moment."
Other key developments:
• US President Joe Biden convened military leaders at White House after planning more weapons assistance to Ukraine
• The food security crisis caused by the war could last into next year, the World Bank warned
• Boris Johnson said peace talks with Russia are likely to fail and compared holding talks with Putin to negotiating with a crocodile
• Wimbledon has barred all Russian and Belarusian players from this year's tennis championships
Mr Danilov, wearing a green band on his right arm - a marker worn by all Ukrainian defenders - said he was confident his country would defeat Russia. But he said victory would come "much faster" if western allies deliver promised weapons as soon as possible.
'War will finish with our victory'
"Now we need heavy weapons, we need armoured vehicles. We need long range artillery... It is very, very necessary to us," Mr Danilov said in an interview on Thursday, noting that the speed of delivery of weapons had increased over the past fortnight.
Asked how the war will end, he said: "It will finish with our victory… If those weapons which our partners promised to us will be delivered as soon as possible it can be much faster."
Speaking candidly, he acknowledged Ukraine's military would not have defended Kyiv as successfully as it did in the first phase of the invasion without western weapons, such as anti-tank and anti-aircraft missiles.
"I say honestly no," Mr Danilov said when asked directly if the defence of the capital would have gone as well without British, US and other allied nations' lethal aid.