The United States will provide Ukraine with a new $500 million infusion of aid to help the government in Kyiv continue paying salaries, pensions and providing services, a Treasury official said Thursday.

The aid, which the official said is necessary to prevent the humanitarian situation in the country from growing more severe as Russia presses on with its invasion, will be announced by Treasury Secretary Janet Yellen during her meeting Wednesday with Ukrainian Prime Minister Denys Shmyhal and Finance Minister Sergiy Marchenko.

The money follows another $500 billion package of support for Ukraine's economy announced last month, and the official said Washington aims to get the aid to Kyiv as quickly as possible.

Shmyhal this week said his government needs $5 billion a month just to continue operations amid the devastation of the nation's economy.

Western countries including the United States have stepped up aid to Ukraine in recent days as fighting rages in the country's east and south, and the IMF and World Bank have rampd up support as well.

President Volodymyr Zelensky has called for more weapons, saying Ukraine still did not have enough, despite billions in Western military aid that has forced Russia to re-focus its offensive away from Kyiv and towards the east of the country.

The IMF has warned of economic devastation both in Ukraine and abroad from the war. 

The conflict will cause the country's economy to collapse 35 percent this year, while Russia's will drop 8.5 percent, and the Washington-based crisis lender also warned this week the "seismic" impacts of the war are spreading worldwide, lowering global growth to 3.6 percent, nearly a point lower than first estimated in January.