By Gabriela Baczynska and Robert-Jan Bartunek

BRUSSELS (Reuters) - The European Union must spend more on defense and uphold accords on climate change and Iran's nuclear program, the bloc's foreign ministers said after mulling future ties with U.S. President-elect Donald Trump, who has cast doubt on all three.

"We understand that there will be more American businesslike approach and therefore there should also be more Europe from our side," said Miroslav Lajcak, the foreign minister of Slovakia, which now holds the EU's rotating presidency.

"But no one has ever questioned the outcome of the election or our readiness to work with the United States," he said after a late Sunday meeting of the bloc.

During the election campaign, Trump suggested he would make U.S. security guarantees for its European allies conditional and has criticized both the international Paris agreement to fight climate change and the deal curbing Iran's nuclear program.

The EU's top diplomat, Federica Mogherini, said the bloc's foreign and defense ministers will decide on Monday to boost their common defense and security capabilities.

"It could be even more relevant in the future," she said.

But, in a clear sign of disunity in the bloc, the British and Hungarian foreign ministers refused to attend the ad-hoc meeting convened after Trump's shock victory at the polls on Nov. 8. The French minister was also not present.

"Europe has multiple problems, but one of them is not America," said Poland's Witold Waszczykowski. "Americans chose a man who is no angel, but is not a child requiring special treatment either."

Britain, which voted in June to leave the bloc, and eastern states such as Hungary and Poland, have criticized the EU for its response to a mass influx of refugees and migrants last year and for centralizing too much power in Brussels at the expense of individual member states.

"These are the problems we should be dealing with and this special consideration of the United States that Europe is showing now is a bit exaggerated," Waszczykowski said.

Fostering closer defense cooperation has long proved difficult in the EU but Germany and France now hope Trump's victory gives the plan renewed momentum.

"I think the debate at the moment is to see how Europe can strengthen its voice in the world. We have already spoken about matters of security and defense," said Belgium's Didier Reynders. "That may also be true for matters of commerce, migration and climate change."

(Reporting by Gabriela Baczynska; Editing by Alan Crosby)