U.S. President Donald Trump, who once celebrated Britain's decision to leave the European Union, insisted Thursday, March 20 that he wants the bloc to remain strong, AFP reports.

"Yes, a strong Europe is very, very important to me as president of the United States," Trump told reporters at a joint news conference with Italy's Prime Minister Paolo Gentiloni.

"And it is also in my opinion -- in my very strong opinion -- important for the United States. We want to see it. We will help it be strong."

Trump's past comments predicting that other countries "will leave" the EU after Britain voted to do so last year rankled European leaders.

European Commission President Jean-Claude Juncker even responded with a joke he was ready to encourage U.S. independence movements if Trump failed to tone down his Brexit support.

However Trump is still insisting most NATO members "owe" money to the alliance, stressing a goal that they all spend two percent of economic output on military expenditure.

In his media conference with the Italian prime minister, Trump focused again on that financial issue.

Gentiloni said his country fully intended to meet that commitment, despite budget limitations.

"We know that this will be a gradual process. It has already begun," he said.