Ukrainian President Zelensky is visiting the UK

Ukrainian president Volodymyr Zelensky arrived in the UK on Wednesday in his first visit since Russia invaded Ukraine last year.

In what is a surprise visit, President Zelensky met with Prime Minister Rishi Sunak in Downing Street and made a speech in Parliament's Westminster Hall before going to Buckingham Palace to meet King Charles.

Speaking to Members of Parliament, Ukraine's president thanked the people of the UK for their help and support during his country's fight against Russia and said he was visiting on "behalf of the brave".

"On behalf of our war heroes who are in the trenches protecting Ukraine against enemy missiles," he said.

President Zelensky's surprise visit to London marks the second time he has left the country since Russia's invasion in February last year. He also made a trip to the United States in December.

In March last year, President Zelensky spoke from his country's capital city Kyiv to Members of Parliament - the first time a foreign leader had given a speech to MPs in the House of Commons.

Continuing his speech on Wednesday, President Zelensky said the UK has been standing with Kyiv "since day one".

He also thanked former UK prime minister Boris Johnson for his support during the conflict and said the UK "is marching with us to the most important victory of our lifetime".

What does Zelensky's UK visit involve?

As well as his speech in front of MPs, President Zelensky met King Charles III at Buckingham Palace and will visit Ukrainian troops who are being trained by British forces.

It follows an announcement that British help with Ukrainian forces will be scaled up this year, with a further 20,000 Ukrainian soldiers receiving training along with fighter jet pilots and elite troops known as marines.

The UK had already announced plans to send tanks to Ukraine, with the Ukrainian military receiving training in how to operate them.

"I thank you Rishi," Zelensky said to the prime minister during his speech. "For this powerful defensive step."

It's also expected the UK will also announce fresh sanctions targeting Russia later - something that Zelensky welcomed, saying they must continue until Russia can no longer afford the war.

• What are sanctions?

What support is Ukraine asking for?

During his speech, President Zelensky repeated his country's request for support in the form of fighter planes.

"Combat aircraft for Ukraine," he says. "Wings for freedom."

Ukraine has continually asked the countries it's allied with for air support - saying advanced jets will help protect its skies from Russian attacks.

Ukraine's aircraft are more than 30 years old, and were built before independence from Russia - then known as the Soviet Union - in 1991.

Ukraine is calling for fighter jets to help its air defence in their ongoing conflict with Russia

But there are concerns among Nato countries, such as the US and UK, that providing aircraft could worsen their relationship with Russia and lead to a further escalation of the conflict.

The UK has focused instead on providing military support in other areas such as training, weapons and tanks.

Asked last month whether the US would be sending planes, President Biden simply said "no", meanwhile the UK said it was "not practical" for it to send its aircraft to Ukraine.

However, stopping short of any announcement of planes being supplied to the country, the UK government has said that training for Ukrainian pilots will ensure they "are able to fly sophisticated NATO-standard fighter jets in the future".

• What is Nato?

Since Russia invaded in February last year, the UK has spent £2.3bn on military assistance, the second biggest amount behind the US. The government has said it plans to match this spending again this year.

What's the latest on the war in Ukraine?

A map of Europe showing Ukraine and Russia

The US, UK and Germany have promised to send tanks in support of Ukraine as the country braces itself for a new wave of Russian attacks later this month.

Russia is attempting to push its forces forward in the south and east of the country, where Ukrainian troops have defended the important city of Bakhmut for six months.