President Zelensky insisted Ukraine is always grateful for Western aid to fight Russia today after an astonishing attack by Defence Secretary Ben Wallace.

Zelensky offered to meet the minister tomorrow after his controversial remarks at a Nato conference in the Baltic. 

At an event in Lithuania, the Defence Secretary said he had bluntly told told Kyiv officials 'I'm not Amazon' when he was presented with a 'shopping list' after an 11-hour drive to visit the war-torn capital.

He went on to suggest that Kyiv had not shown enough 'gratitude' for the materiel support it had received since the February 2022 invasion.  

Rishi Sunak publicly distanced himself from his senior minister's complaint, saying the Mr Zelensky had 'expressed his gratitude for what we have done on a number of occasions'.

It came after the Ukrainian war leader had expressed his frustration at the reluctance of the 31 member states to agree a firm timetable for membership.

Joe Biden's administration has also told Ukraine that the US 'deserves a degree of gratitude' for its billions of dollars in military support to the war-torn nation.

In surprisingly strong remarks at the event in Vilnius, Mr Wallace told reporters: 'There is a slight word of caution here which is that, whether we like it or not, people want to see gratitude.'

'My counsel to the Ukrainians... you're persuading countries to give up their own stocks. And yes the war is a noble war and yes we see it as you doing a war for not just yourself but our freedoms.

'But sometimes you've got to persuade lawmakers on the Hill in America. You've got to persuade doubting politicians in other countries that it's worth it and it's worthwhile and they're getting something for it.'

A bemused Mr Zelensky later said he was 'always grateful' for foreign aid, adding: 'I don't clearly understand the questions. We were always grateful to the UK, to the prime ministers and to the minister of defence.'

And Mr Sunak told his own press conference at the event: '(He) expressed his gratitude for what we have done on a number of occasions, not least in his incredibly moving address that he made to Parliament earlier this year and he has done so again to me, as he has done countless times when I have met him.

'So I know that he and his people are incredibly grateful for the support we have shown, the welcome that we have provided to many Ukrainian families, but also the leadership we have shown throughout this conflict.' 

Mr Sunak today told Mr Zelensky he belonged in Nato as he assured him 'real progress' had been made on providing security guarantees for Kyiv. 

Mr Zelensky said it was 'logical and understandable' that Ukraine could not be admitted immediately as the struggle against Russia meant the conflict would develop into a world war.

But he said Nato had sent 'signals' that were 'important' when it came to Ukraine becoming a member state.

'Already we can hear some confident statements (about) when the conditions will be met,' said Mr Zelensky, who was speaking through a translator.

As well as holding talks with Mr Sunak, the Ukrainian leader also met other G7 heads of state, including German chancellor Olaf Scholz and Canadian prime minister Justin Trudeau.

He is expected to meet US president Joe Biden later on Wednesday.

Labour's shadow defence secretary John Healey said: 'The Ukrainians are fighting for the future and the freedom of their country.

'President Zelensky wants more military help yesterday, of course he does. What he doesn't need is lectures on gratitude, especially when they overshadow a successful summit in which NATO is stronger and the support for Ukraine is greater.'

This morning US National Security Advisor Jake Sullivan issued a thinly-veiled warning to Kyiv.

He angrily dismissed claims from Ukrainian anti-corruption activist Daria Kaleniuk that the president 'was afraid of Russia' by not setting out a timeline for Ukraine to join the Brussels-based military alliance. 

'The United States of America has stepped up to provide an enormous amount of capacity to help ensure that Ukraine's brave soldiers have the ammunition, air defense, the infantry, fighting vehicles, the mine clearing equipment and so much else to be able to effectively defend against Russia's onslaught and to take territory back as well,' he said.

'I think the American people do deserve a degree of gratitude from the United States government for their willingness to step up and from the rest of the world as well.'

In a thinly-veiled swipe at Zelensky's criticism of his Western allies, Sullivan said some of the charges leveled against the U.S. were 'entirely unfounded and unjustified.'

The United States is by far the largest donor of military support to Ukraine, offering more than $46 billion worth of hardware to Kyiv, according to data from a respected German think-tank.

Lawmakers in Congress have earmarked as much as $100 billion, but not all of that aid has yet been drawn down to help the Ukrainian government. 

Most of the weapons shipped to Ukraine are also made in the U.S., boosting jobs in the country's key defense sector.

The second largest donor, by contrast, is Britain, which has offered up just over $6 billion, according to the Kiel Institute for the World Economy's Ukraine Support Tracker.