Donald Trump has launched another extraordinary attack on Spain after declaring the country ‘a lost cause’ at the NATO summit in Turkey.

In typical rambling fashion, the US president said he would halt ‘all trade and visits’ over Madrid’s refusal to dramatically increase defence spending.

Speaking alongside NATO Secretary General Mark Rutte at the alliance’s summit in Ankara on Wednesday, Trump singled out Spain as his main target, branding it ‘a terrible partner’.

‘Spain is a lost cause. By the way, we don’t want to do any business with Spain anymore,’ Trump said.

‘I want them to cut it. Spain is a terrible partner in NATO. They don’t participate. They don’t pay. I don’t want anything to do with Spain. Cut all trade with Spain, including visits.’

The comments mark the latest escalation in a months-long row between Trump and the Spanish government over defence spending.

Spain has repeatedly resisted pressure to commit to spending 5% of its GDP on defence, insisting that a lower level of spending is sufficient to meet its NATO obligations.

Prime Minister Pedro Sanchez has argued that raising military spending to 5% would be ‘unreasonable’ and unnecessary.

Trump has repeatedly criticised Spain over the issue, previously threatening trade retaliation after Madrid refused to allow US forces to use the jointly operated bases at Rota and Moron during military operations against Iran.

Despite Trump’s remarks, any attempt to suspend trade with Spain would face significant legal and diplomatic hurdles, as trade policy is negotiated between the US and the EU rather than with individual member states.

The Spanish government has previously stressed that bilateral trade relations are governed through the EU framework.

So far, there has been no indication from the White House of how or when Trump’s latest demand to cut trade and visits would be implemented.