Video report by ITV News Political Editor Robert Peston

Striking a trade deal with Donald Trump will not be “plain sailing”, Boris Johnson warned ahead of his first meeting with the US President.

The Prime Minister will sit down with Mr Trump on Sunday at the G7 summit in Biarritz, following weeks of public praise from the US leader for the new man in Number 10.

But Mr Johnson said a trade deal – which both sides have said they want – would require compromise from Washington while keeping key UK interests including the NHS off the table.

As well as his meeting with Mr Trump, the Prime Minister will also discuss Brexit with European Council president Donald Tusk after the pair clashed on Saturday over who would be to blame if no divorce deal was struck before the UK’s exit from the European Union on October 31.

Ahead of the meeting with Mr Johnson, the US Government had talked up the prospect of a new era in the special relationship.

But Mr Johnson told reporters accompanying him at the G7 summit that while there was “a massive opportunity” for Britain, “it is not all going to be plain sailing”.

“There remain very considerable barriers in the US to British businesses which are not widely understood,” he said.

Boris Johnson will meet US President Donald Trump at the G7. Credit: AP

It came after Donald Tusk said he hopes Mr Johnson will not want to go down in history as Mr 'No Deal'.

The European Council President added he was willing to cooperate with the UK over Brexit but "one thing I will not cooperate on is no deal".

Speaking at the G7 summit in Biarritz, France, the President of the European Council said he will be meeting Mr Johnson on Sunday to discuss Brexit.

Mr Johnson says the UK will leave the European Union on October 31 regardless whether a deal has been agreed or not.

"The EU was always open to cooperation; when David Cameron wanted to avoid Brexit; when Theresa May wanted to avoid a no deal Brexit and we will also be ready now to hold serious talks with Prime Minister Johnson," Mr Tusk said.

"The one thing I will no cooperate on is no deal. I still hope Prime Minister Johnson will not want to go down in history as 'Mr No Deal'. We are willing to listen to ideas that are operational, realistic and acceptable to all member states, including Ireland."

Speaking to reporters on the plane to Biarritz, Boris Johnson hit back over Mr Tusk's comments, saying: "I have made it absolutely clear I don't want a no deal Brexit.

"But I say to our friends in the EU, if they don't want a no-deal Brexit then we have got to get rid of the backstop from the treaty.

Boris Johnson is in Biarritz for the G7 summit. Credit: AP

"If Donald Tusk doesn't want to go down as 'Mr No Deal Brexit' then I hope that point will be borne in mind by him too."

Mr Johnson's meeting with Mr Tusk follows talks with German chancellor Angela Merkel on Wednesday and French president Emmanuel Macron on Thursday.

After that meeting, the prime minister said said the "mood music" was positive, but getting the changes he wants to the Withdrawal Agreement would not be easy and he was "telling people not to hold their breath" for a breakthrough.

After landing in Biarritz Mr Johnson was asked by ITV News Political Editor Robert Peston whether trade tensions between America and China would be discussed with President Trump.

Emmanuel Macron and his wife Brigitte greeted Canadian leader Justin Trudeau in Biarritz. Credit: AP

Mr Johnson responded: "On trade with China and on free trade generally, you betcha."

When asked whether Brazil president Jair Bolsonaro's reluctance to tackle Amazonian forest fires would stand in the way of a trade deal with South America, Mr Johnson appeared to say no.

He said: "There are all sorts of people who will take any excuse at all to interfere with free trade and to frustrate trade deals and I don't want to see that and I do want to see the tragedy in Brazil tackled properly."

At a meeting with Canadian counterpart Justin Trudeau, Prime Minister Boris Johnson said the leaders would be "working flat out".

He said the G7 was not a "wonderful boondoggle here in some posh hotel in Biarritz".

"We are going to be working flat out on issues that will make a material difference to the quality of life of everyone in our countries and around the world."

On the major issues being discussed he said Canada and the UK are "side by side".

Prior to the G7 summit, Mr Johnson offered a positive outlook for the UK's future.

Boris Johnson has met with Canadian Prime Minister Justin Trudeau. Credit: AP

"Some think Britain’s best days are behind us. To those people I say: you are gravely mistaken," the prime minister said.

Leaders from around the world are meeting in Biarritz to discuss a variety of issues.

"This is another G7 summit which will be a difficult test of the unity and solidarity of the free world and its leaders", Mr Tusk said.

"There is still no certainty that the group will be able to find common solutions and the the the global challenges today are really serious. Or whether to focus on senseless disputes among each other.

"The last years have shown it is increasingly difficult for all of us to find common language when the world needs our cooperation more, not less. This may be the last moment to restore our political community."

Mr Johnson will meet US President Donald Trump on Sunday morning.

The pair spoke on the phone on Friday evening ahead of their meeting - their fourth official phone call since Mr Johnson took office a month ago and the second call this week.