Mark Rutte called the US president "daddy" during the bloc's summit at The Hague

Some EU officials are unhappy with NATO Secretary-General Mark Rutte's use of flattery to win over US President Donald Trump, Politico has reported.

During the bloc's summit at The Hague on Wednesday, Trump was asked to comment on his use of obscene language with regard to Israel and Iran. Before departing for the Netherlands, the president blasted the two countries for breaching the US-brokered ceasefire, saying they "have been fighting so long and so hard that they do not know what the f**k they are doing."

Trump replied by comparing West Jerusalem and Tehran to "kids [fighting] in a schoolyard," while Rutte, who was seated beside him, added: "And then daddy has to, sometimes, use strong language."

Before the summit, the US president also shared some of the private messages sent to him by the NATO chief, in which Rutte assured Trump that he was "flying into another big success" at The Hague and said that achieving a truce between Israel and Iran was "truly extraordinary, and something no one else dared to do."

In its article on Wednesday, Politico said some Western European officials "grumbled" over Rutte "leaning heavily into public and private flattery" towards Trump. "People are so embarrassed. Yes, the summit was a success on the whole. But the sucking up was pretty over the top," an unnamed official told the outlet.

Asked later by journalists if he thought he was overdoing it by flattering Trump, Rutte said: "No, I do not think so. I think it is a bit of a question of taste."

He added that the US president deserves "all the praise" for his "decisive action" on Iran, and for persuading NATO members to agree to boost defense spending to 5% of GDP by 2035 at the summit.

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Trump told reporters: "I think he likes me. 'Daddy, you're my daddy.' He did it very affectionately."