Fears are mounting that Donald Trump wants a 'peace deal' with Vladimir Putin that could fatally undermine NATO.

Ministers are becoming increasingly alarmed that the US president could offer the Russian president deep concessions such as withdrawing forces from Europe.

Mr Trump is expected to have a high-stakes meeting with Mr Putin next month - straight after he attends a NATO summit in Brussels.

But there are concerns he could try the same tactics he used in his face-to-face encounter with North Korea's Kim Jong Il - such as cancelling joint military operations.

Ministers are becoming increasingly alarmed that the US president (pictured at a rally in North Dakota last night) could offer the Russian president deep concessions such as withdrawing forces from Europe

US national security adviser John Bolton (right) met Vladimir Putin at the Kremlin yesterday as he laid the plans for the summit between the leaders

Mr Trump has already called for Russia to be readmitted to the powerful G7 bloc of nations, despite an outcry from European states over its aggressive foreign policy and meddling. Theresa May has been pushing for Moscow to be isolated after the nerve agent attack on a former Russian spy in Salisbury.

The president has also repeatedly railed at NATO states for failing to pull their weight on military spending and relying on America might for their security.

Just six members of the bloc - including Britain - meet the target of allocating 2 per cent of GDP to defence.

One Cabinet minister told the Times: 'What we're nervous of is some kind of Putin-Trump 'peace deal' suddenly being announced.

'We could see Trump and Putin saying, 'Why do we have all this military hardware in Europe?' and agreeing to jointly remove that.'

'It's hard to be against peace, but would it be real peace?'

Mr Trump has suggested his meeting with Mr Putin could take place in Helsinki, FInland or Austria.

Theresa May (pictured at Downing Street yesterday) has been pushing for Moscow to be isolated after the nerve agent attack on a former Russian spy in Salisbury

Mr Trump's national security adviser John Bolton met his UK counterpart Sir Mark Sedwill for talks this week.

Mr Bolton met Mr Putin at the Kremlin yesterday as he laid the plans for the summit between the leaders.

'I think the fact of the summit itself is a deliverable,' he said afterwards.

'There are a lot of issues to talk about that have accumulated, and I think this was one of the reasons why President Trump believed so strongly that it was time to have this kind of meeting. And as you can see, President Putin agreed.'

US Secretary of State Mike Pompeo raised the prospect of a deal being done to rehabilitate Mr Putin into the international community.

'The president deeply believes that having Russia be part of these important geostrategic conversations is inevitable, and there's a long history of that,' he said.