Ukraine has agreed with two US firms to jointly manufacture vital 155mm artillery shells in the country, a minister says, although production will not start for at least two years.
Demand for 155mm rounds soared following Russia's full-scale invasion of Ukraine in 2022.
The US and allies have sent Ukraine more than two million and are trying, with limited success, to increase production to replenish stocks.
"We have agreements with two leading American companies to jointly produce, in Ukraine, 155-calibre ammunition," Oleksandr Kamyshin, minister for strategic industries, said in televised comments.
But he noted that Ukraine had never produced such shells and it would be "a minimum of two years, a maximum of three" before production could begin.
The announcement follows a two-day Ukraine-US defence conference held in Washington DC which included bilateral meetings to discuss Ukraine's battlefield plans for 2024 and measures to make it happen.
Ukraine and the US signed a letter of intent at the forum to speed up weapons co-production and technical data exchange to meet the urgent needs of the Ukrainian army in air defence systems, maintenance and production of critical ammunition.
Ukraine's defence sector - which for decades was dogged by underinvestment, red tape and corruption - is trying to compete with Russia's far more advanced military industry and high budget support.
And, as the war nears the end of its second year with no end in sight, concerns are growing that foreign supplies may be faltering as political support erodes and manufacturing capacity is still lacking as allies' own stockpiles dwindle.
On Wednesday, Republicans in the US Senate blocked an emergency bill that would provide about $US60 billion ($A91 billion) in military and economic support for Ukraine, threatening hopes that the funds can be approved by the end of the year.
"For us, it is a matter of survival to create a military industry that matches the scale of the enemy’s industrial capacity," Ukrainian Defence Minister Rustem Umerov was quoted as saying on the conference website.
Ukraine also hopes that it can become integrated into the military landscape of its European and US allies by promoting joint weapons production and supplies in a "common defence industry space".
President Volodymyr Zelenskiy said Ukraine did not want to rely solely on military aid from allies and aimed to become a donor of security for neighbours in the future.