Diplomats say that support from European NATO countries and Canada will be included in the summit's final declaration.
This involves 30 billion euros (331 billion SEK) annually - in the form of EU loans and funds that individual countries have already pledged.
The largely symbolic move is intended to show US President Donald Trump, who is more isolationist, that allies have taken over the financing of Ukraine's fight against Russia.
It is also intended to show Ukrainian President Volodymyr Zelenskyy, who is due to attend the summit, that foreign support remains firm.
