US President Joe Biden has condemned a wave of Russian missile strikes that killed at least 38 people in Ukraine as a "horrific reminder of Russia's brutality", as he vowed to strengthen Kyiv's air defences.

At least 190 were injured across the country, including some at a children's hospital in the capital Kyiv on Monday.

Russia has denied it fired at the Kyiv hospital, but the UN said it was highly likely Moscow was behind the blast - a conclusion shared by analysts who spoke to BBC Verify.

It comes as Mr Biden prepares to host a Nato summit in Washington on Tuesday.

The US president said further boosts to Ukraine’s air defences would be announced at the meeting.

Leaders from the 32 Nato member states, their partner countries and the EU are gathering to mark the 75th anniversary of the bloc. Ukraine's President Volodymyr Zelensky is also expected to attend.

He has been urging Western allies to step up deliveries of air defences for months, amid increased Russian attacks. UN officials said May was the deadliest month for civilian casualties in almost a year.

The summit will focus on defence and deterrence in the context of the Russian invasion of Ukraine.

Ukraine is not a Nato member, but it has asked to be admitted as soon as possible after its war with Russia ends. Nato's outgoing secretary general, Jens Stoltenberg, has said it is "inevitable" that Ukraine will eventually become a member, but not until after the war.

Russia fiercely opposes Ukraine joining the bloc, fearing it would bring the alliance's forces too close to its own territory.

"We will be announcing new measures to strengthen Ukraine’s air defences to help protect their cities and civilians from Russian strikes," Mr Biden said.

"I will be meeting with President Zelensky to make clear our support for Ukraine is unshakeable."

The UN Security Council is also meeting on Tuesday at Ukraine’s request.

UN Secretary General Antonio Guterres joined Western officials in condemning Russia's missile attack on Ukraine.

Kyiv's mayor, Vitali Klitschko, declared 9 July as a day of mourning following the deadly attacks on the capital.

UN officials said May was the deadliest month for civilian casualties in almost a year.

Two people died when a missile flattened part of the Ohmatdyt Children's Hospital - Ukraine's biggest paediatrics facility - and a search for survivors beneath the rubble was completed on Tuesday morning.

The Kremlin has denied carrying out the attack, and foreign ministry spokeswoman Maria Zakharova claimed the blast was caused by a misfiring NASAMS air defence missile.

But the UN's human rights monitoring mission in Ukraine said there was a high likelihood that Russia carried out the attack on the children's hospital.

Officials said video footage and a site assessment indicated the building was directly hit by a Russian missile.

BBC Verify has analysed two videos showing a missile striking the hospital, and have geolocated each to confirm the strike location.

Six munitions experts who saw the footage unanimously agreed that the missile was not an air defence missile.

They all said they cannot be definitive about the type of munition used, but formed a consensus it was likely an air-launched Russian missile. Four of the six specifically mentioned a Russian Kh-101 missile as a possibility, in line with the claim by Ukraine's security services (SBU). The agency said on Tuesday that it had "unequivocal" evidence Russia was behind the attack.

Speaking to the BBC, one expert expressly noted the presence of a small turbofan engine at the rear of the missile, which they observed was consistent to the Kh-101.

President Zelensky called the attack "brutal" and described his Russian counterpart Vladimir Putin as a "bloody criminal".

Pictures from the scene of the blast at the Kyiv hospital - which specialises in cancer treatment and organ transplants - showed children hooked up to IV drips sitting outside the damaged facility awaiting evacuation.

Mr Zelensky said that Russia had launched more than 40 missiles on Monday, damaging almost 100 buildings in Kyiv, Dnipro, Sloviansk, Kramatorsk and his home town of Kryvyi Rih.

His government in Kyiv says it desperately needs new US-made Patriot air defence systems. But Western officials have been reluctant to surrender any more of the limited number such surface-to-air batteries scattered across the Nato alliance.

The UK's new Prime Minister, Sir Keir Starmer, also condemned the attack, calling it "the most depraved of actions".

Britain has been one of Ukraine's key Western allies, and Sir Keir has vowed that his new administration will maintain support for Kyiv. He is set to meet President Biden at the White House on Wednesday on the sidelines of the Nato summit.

Mr Peskov told the BBC that the Kremlin would be following the gathering "extremely closely".

"It is an alliance which has repeatedly and openly declared that its aim is to deliver Russia a strategic defeat on the battlefield," Mr Peskov.

Meanwhile, Russian officials said a fire had broken out at a power substation in the Rostov region, bordering Ukraine, after overnight drone attacks.

The regional governor said four people were killed and 20 injured in attacks by Ukraine over the past day.

Additional reporting by Benedict Garman.