US President Donald Trump changed his stance on Ukraine due to anger at the media's coverage of the Alaska summit as a victory for Russian leader Vladimir Putin.

This is reported by politics with reference to sources.
“Media coverage of the Alaska summit, called 'Putin's victory,' angered Trump,” the insider said.
As the publication notes, the US leader “received nothing” during or after the summit. In addition, there is an opinion that Trump's change of view on Ukraine was influenced by dissatisfaction with the visit of Putin and North Korean leader Kim Jong-un to China in September, as well as Kiev's persistence in correcting mistakes in relations with Trump.
Previously, Mr. Trump promised to think about approving the transfer of long-range weapons to Ukraine. According to him, Ukraine intends to attack and is therefore asking Washington to provide weapons.