Il Nuovo Postiglione - Zelensky in London for whirlwind tour of Europe ahead of US vote

Starmer greeted Zelensky shortly after 9:00 am (0800 GMT) on a red carpet outside Downing Street, where the Ukrainian leader was also expected to meet new Nato chief Mark Rutte.

After London, Zelensky was due to visit France and Italy on Thursday, before meeting Pope Francis at the Vatican on Friday and German Chancellor Olaf Scholz later the same day.

The Ukrainian leader, dressed in his trademark military fatigues, is seeking to secure as much financial and military backing as possible during the tour, with US support in doubt if Donald Trump wins November's vote.

Kyiv could be facing its toughest winter yet, with Russia launching fresh waves of strikes on the country's power grid and advances across the eastern frontline.

Zelensky's packed itinerary involves him travelling to the UK, France, Italy and Germany all within the space of less than 48 hours.

On Thursday afternoon he will be in Paris for a meeting with French President Emmanuel Macron, and is later expected to travel to Rome for talks with Italian Prime Minister Giorgia Meloni, according to Italian media.

Zelensky has an audience with Pope Francis in the Vatican on Friday morning, and will meet Scholz in Berlin on the same day, according to a German government spokeswoman.

A key meeting with international allies planned for Saturday was postponed after US President Joe Biden called off a planned European trip to focus on the threat from Hurricane Milton.

- Pivotal US vote -

Zelensky says his country desperately needs more aid to tip the balance of the war and secure victory on the battlefield as Russia captures dozens of small towns and villages in the disputed east.

He also still wants clearance to use long-range weapons supplied by allies, including the United States, to strike military targets deep inside Russia.

On the ground, questions are growing among Ukrainian soldiers about the long-term strategy of the offensive into Russia's Kursk region, given Russia's push in the east of Ukraine.

"If this is a short-term operation, it will strengthen us," Bogdan, a serviceman sitting at a cafe in Druzhkivka, near Kramatorsk, told AFP.

"If it's a long-term operation and we plan to stay in Kursk, it will deplete our main resources."

Ukraine relies on billions of dollars worth of financial and military aid from Washington to fight Russia's invasion, and the US presidential election in November could prove pivotal.

The German-based Kiel Institute warned Thursday of a significant fall-off in Western aid to Kyiv if Republican candidate Trump wins the November 5 election.

The institute said military and financial aid expected in 2025 could halve to about 29 billion euros ($31 billion).

"Starting next year, Ukraine could face a significant aid deficit," it said.

Trump has promised to end the war "in 24 hours" if he is elected -- a prospect Kyiv fears means being forced to make massive compromises to achieve peace.

Vice President and Democratic rival Kamala Harris has said she would not meet with Russian leader Vladimir Putin for peace talks if Ukraine was not also represented.

Zelensky has rejected any peace plan that would involve ceding territory to Russia, arguing Moscow must withdraw all its troops from inside Ukraine's borders to achieve lasting peace.

Zelensky's visit to Downing Street was his second since Starmer's Labour party secured a landslide general election triumph on July 4.

He received a standing ovation from senior UK ministers when he became on July 19 the first foreign leader to address the British cabinet in person since 1997.

Britain has been one of Kyiv's biggest backers in its two-year-plus fight against Russia's invasion, committing to delivering £3.0 billion ($3.9 billion) of military aid every year for as long as needed.

M.Lombardi--INP