CNN explains how Trump made final decision to publicly attack Zelenskyy

US President Donald Trump's public attack on his Ukrainian counterpart Volodymyr Zelenskyy was preceded by a growing sense of frustration in the White House.

CNN recalls that for many years, Trump has been sceptical of Zelenskyy, questioning his decisions and – in an episode that became known during Trump's first impeachment – demanding that he launch an investigation into his then-rival Joe Biden.

Lately, however, Trump aides have been closely monitoring Zelenskyy's public statements – particularly his criticism of the US excluding Ukraine from talks with Russian officials in Saudi Arabia this week – with growing unease.

Sources say the frustration had been growing until Wednesday. But it culminated after Zelenskyy told reporters at his office in Kyiv that Trump was a victim of disinformation.

An official who travelled with Trump said that Trump privately told aides who were with him in Florida that he wanted to respond directly, leading to a post on Truth Social, which he posted on his way to his Miami golf club and expanded on his remarks in front of hundreds of people at an evening investment conference in Miami organised by the Saudi Arabian Sovereign Wealth Fund, where US and Russian officials held talks earlier this week.

"It’s a frustration. There is a strong and legitimate feeling that this brutal war has to stop and that this pathway is being diminished through Zelenskyy’s public statements," a second White House official told CNN.

However, Zelenskyy said that the end of the war envisaged by Trump is very similar to what Russia is asking for. Members of Trump's administration have already ruled out the possibility of Kyiv's membership in NATO and said that US troops would not help guarantee Ukraine's security after the war ends.

For these reasons, he says he cannot help but speak out.

Many of Trump's allies said Zelenskyy should have anticipated Trump's anger.

"The idea that Zelenskyy is going to change the president’s mind by badmouthing him in public media, everyone who knows the president will tell you that is an atrocious way to deal with this administration," US Vice President JD Vance told The Daily Mail.

Explaining Trump's harsh public statements, White House officials insist that his primary – in fact, only – goal is to end the war in Ukraine.

"Yet how he achieves that objective while castigating Zelenskyy and aligning himself with Russian talking points isn’t clear," CNN noted.