Delegates were in London on Wednesday for a donor conference to help Ukraine repair damage inflicted by Russia's war of aggression.

The scale of devastation is enormous, with some experts saying Ukraine needs the equivalent of the Marshall Plan that helped rebuild Europe after World War II.

What have leaders been saying?

UK Prime Minister Rishi Sunak opened the conference as co-host with Ukrainian President Volodymyr Zelenskyy, who appeared remotely.

Zelenskyy said real projects for the reconstruction of Ukraine were needed.

"We must move from vision to agreements and from agreements to real projects," he said. "There is a Ukrainian delegation that will present concrete things," he said.

Sunak emphasized the need for greater private investment, something that he hoped could be encouraged with a new framework to insure companies against war risks.

"Before this terrible war, Ukraine's economy was becoming a huge investment opportunity," said Sunak. "The truth is that opportunity is still there today. In fact, the war has only proved how much Ukraine has to offer."

German Foreign Minister Annalena Baerbock said there needed to be a link between Ukraine's recovery from the war and its accession to the European Union.

"I'm convinced that we need to further link Ukraine's recovery and the EU accession process," Baerbock said in London. "Our goal is to help rebuild a Ukraine that is fit for EU."

European Commission's President Ursula von der Leyen outlined investment plans for the country but said they were just the beginning.

"This is for Ukraine's immediate needs. But let's talk about the future. I believe the European Union has a special responsibility," von der Leyen said.

"Ukrainians tell us that when they imagine their future, they see Europe's flag flying over their cities. And I have no doubt that Ukraine will be part of our union."

What is happening at the conference?

The International Ukraine Recovery Conference 2023 is the second to be held since Russia invaded Ukraine in February last year.

More than 1,000 representatives from 61 countries, including private investors, are attending.

Before the event, Baerbock noted that the challenge was even greater after the destruction of the Kakhova dam, which has flooded large swaths of land along the lower Dnieper River.

Germany was ready to provide "massive new humanitarian aid ready to the families worst affected by destruction, flooding, and displacement," Baerbock said, promising a "reconstruction offensive."

The US secretary of state was expected to announce a new package from Washington at the fundraising forum assistance.

On Tuesday, the European Commission asked member states to back a €50 billion ($55 billion) package to support Ukraine over the next four years.

What will it all cost?

At the first conference, held in Lugano, Switzerland, in July last year, Ukraine's allies committed to supporting the country through an expensive and decades-long recovery.

Ukrainian Prime Minister Denys Shmygal told them the cost of rebuilding could reach $750 billion — or even more.

A more recent study by the World Bank, the UN, the European Union and the Ukrainian government placed the estimate for the wider recovery of the economy at $441 billion.

In terms of immediate needs, the World Bank estimates Ukraine needs $14 billion to repair the damage caused by the fighting.