Ukrainian President Volodymyr Zelenskyy met British Prime Minister Rishi Sunak on the sidelines of the G7 summit in Hiroshima on Saturday.
They embraced and sat side-by-side for discussions. The leaders met in the UK on Monday as Mr Zelenskyy visited allies and appealed for F-16 fighter jets to use in Ukraine's war against Russia.
“Good to see you,” Mr Sunak said. “You made it.”
When asked if it was a good day for Ukraine, Mr Zelenskyy smiled, nodded and said “thank you so much”.
Ukraine is likely to receive fighter jets after US President Joe Biden authorised western allies to transfer them.
“Japan. G7. Important meetings with partners and friends of Ukraine. Security and enhanced co-operation for our victory. Peace will become closer today,” Mr Zelenskyy tweeted.
He flew into Japan for what had been a surprise visit until the news leaked out on Friday.
Mr Biden informed his allies at the conference that he will give legal permission to allow the American-made planes to be donated to Kyiv.
Mr Biden, who is attending the G7 with France, Italy, Germany, Japan and Canada, as well as the EU, also announced training for Ukrainian pilots.
Mr Sunak welcomed the decision, having pressed allies to provide Ukraine with the aircraft its president with the jets he has been calling for.
The RAF does not have any F-16s. Washington must legally approve their export.
Mr Zelenskyy is expected to take part in meetings with the G7 on Sunday.
Russia was expelled from the group after its 2014 annexation of Crimea.
On Saturday, Mr Sunak met French president Emmanuel Macron for discussions at the summit and had a short “brush-by” meeting with German Chancellor Olaf Scholz.
They discussed providing military aid and “longer-term security assistance” to Ukraine as well as tackling small boat crossings of the English Channel, Downing Street said.