Donald Trump spoke to reporters hours after plunging the stock market into havoc – sparking fears of a recession – with his raft of tariffs, including the 10% on the UK

An upbeat Donald Trump has insisted the tariffs saga is “going very well”.

The US President’s trade war sent world economies down the pan on Thursday, and saw a staggering $2.2trillion wiped off global stock markets. Yet when asked by a reporter for his reaction to the worst stock market drop in years, Mr Trump, 78, said: “The markets are going to boom, the stock is going to boom, the country is going to boom.”

Compared the United States to a sick patient in need of surgery, the maverick added: “I think it’s going very well. We have an operation, like when a patient gets operated on and it’s a big thing. I said this would exactly be the way it is.”

Yet, Wall Street was a sea of red as US markets opened for the first time since the minimum 10% tariff were unveiled late on Wednesday. The benchmark S&P 500 index slumped more than 4% in early trading. Global companies, including Nike, Adidas and Puma, have suffered huge losses already.

READ MORE: UK hits back at Donald Trump after his tariff blows – and has huge retaliatory threat

Mr Trump has always said the US economy will grow as a result of the move, which also included 20% tariffs on European Union nations. The politician implied it is now up to those countries – and other global players – to “make a deal” with the US.

And Sir Keir Starmer on Thursday hinted his team is already in the process of negotiation. Speaking at an event in Chesterfield, Derbyshire, the PM said: “I need to act in the national interest. The choice before us is whether to jump into retaliatory action with both feet at the get-go, or continue with our calm approach to negotiate a trade deal to mitigate tariffs if we can.”

Should the “calm approach” fail, it is believed the UK will threaten tariffs on 8,000 US products including toilet seats, cheese and bourbon whisky. Britain has published a 400-page list of the US goods, such as these and car parts, on which any future retaliatory tariffs could be imposed.

Jonathan Reynolds, Business Secretary, said: (The) talks with the US will continue to reflect our mandate to deliver economic stability, as we press the case for a trading relationship that supports businesses on both sides of the Atlantic.”

The defiant politician also told Sky News Mr Trump “won’t get his own way” despite his vow on Wednesday in Washington. In this interview, Mr Reynolds added: “There’s a set of complaints from the US about how some of the current global trading arrangements work. They won’t get their own way on all of that. But there are some things to talk about: if the US is the world’s number one customer, they do want to be treated like that.”