The United States is moving ahead with millions of dollars in aid for Ukraine's military, money that had until now been held up by the White House.

White House officials Thursday confirmed the release of $250 million in funding from the Pentagon and another $141 million in financial assistance from the State Department shortly before lawmakers were set to admonish the administration for the delay.

"The Departments of State and Defense are proceeding with the obligation of all military and security assistance funding to Ukraine," according to a senior administration official. "The Administration supports Ukraine's efforts of reform and self-defense, and these funds will advance Ukrainian efforts toward those ends."

Earlier Thursday, the State Department announced it had been cleared to release the $141 million in aid.

FILE - R. Clarke Cooper, Assistant Secretary of State for Political-Military Affairs, is seen in an official State Department photo.

Speaking to reporters in Washington, Assistant Secretary for Political and Military Affairs R. Clarke Cooper called it part of "a whole host of security assistance that we have outlined and identified for Ukraine."

That was followed by the announcement that $250 million in Pentagon aid, for additional training, and equipment for Ukrainian forces, also was being released.

"U.S. assistance has saved lives while helping to build Ukraine's long-term defense capacity," a State Department official said, speaking on condition of anonymity. "We remain committed to a robust partnership with Ukraine."

Push for action

Both Republican and Democratic lawmakers had become increasingly frustrated, and vocal, about continuous delays in sending the aid to Ukraine, which has been struggling against Moscow-backed separatists following Russia's invasion and annexation of Crimea in 2014.

FILE - Sen. Rob Portman, R-Ohio, attends a ceremony at the Ohio Statehouse, in Columbus, Ohio, Jan. 14, 2019.

"Our financial support is absolutely crucial," Republican Senator Rob Portman, co-chair of the Senate Ukraine Caucus, said in statement Thursday, adding he had spoken with President Donald Trump the night before.

"With this funding we will provide vital assistance to help the Ukrainian military continue on their path of increasing their ability to defend their homeland against any threat," he said.

Portman was one of five senators who signed a letter to Trump's budget director earlier this month, expressing "deep concerns" that the funding was being held up.

Some administration officials had said the White House was reluctant to release the money due to high levels of corruption in Ukraine.

'Defeat' corruption

But U.S. lawmakers have said they are optimistic about efforts by new Ukrainian President Volodymyr Zelenskiy to address those concerns.

FILE - Ukrainian President Volodymyr Zelenskiy delivers a speech at the Elysee Palace, in Paris, June 17, 2019.

"Zelenskiy says we're not just going to fight corruption, we're going to defeat it," Republican Senator Ron Johnson, who met with Zelenskiy in Kyiv, told VOA's Ukrainian service Wednesday. "That's a tall order, but it shows a laudable goal, so we were very encouraged."

Since 2014, the U.S. has given Ukraine about $1.6 billion in security assistance.

The newly released funds are slated to pay for ongoing training programs for Ukraine's military as well as improvements to the country's maritime capabilities.

The money will also pay for sniper rifles, rocket propelled grenades, counter artillery radars, electronic warfare detection systems and night vision goggles.