Having failed to persuade US President Donald Trump to give Ukraine Tomahawk cruise missiles, President Volodymyr Zelensky is concentrating on purchasing Patriot air defence systems.
Zelensky said in his evening video message on Monday that he was "working with America so that Ukraine can receive the required number of Patriot systems after all."
"This is not an easy task, but it is one of the security guarantees for Ukraine and will work in the long term."
He said he had spoken to the manufacturers of the Patriot and other weapons systems in Washington.
"There is certainly a willingness to cooperate with Ukraine - they trust Ukraine," Zelensky said.
However, approval for such weapons purchases is also needed at a political level.
During a visit to Washington last week, Zelensky did not receive the expected commitment from the US to provide the Tomahawks, which Ukraine could also use to hit targets deep in the Russian hinterland.
To date, Ukraine only has a few Patriot air defence systems, which were mainly supplied by Germany or with German assistance.
They have proven to be the most effective protection against Russian ballistic missiles.
