"I have authorized, pursuant to a delegation from the President earlier today, the immediate drawdown of security assistance valued at up to $100 million to meet Ukraine's urgent need for additional anti-armor systems," Blinken said in a statement.

He added that the "world has been shocked and appalled by the atrocities committed by Russia's forces in Bucha and across Ukraine."

Pentagon spokesman John Kirby, in a separate statement, said that the extra funding would be used "to meet an urgent Ukrainian need for additional Javelin anti-armor systems."

Ukrainians have been using the shoulder-launched missiles "so effectively to defend their country," he noted.

On April 1, the Pentagon announced an extra $300 million in military assistance.

Kirby said the latest tranche brought the US military aid to Ukraine to "more than $1.7 billion since the beginning of Russia's premeditated and unprovoked invasion on February 24," and more than $2.4 billion since the beginning of US President Joe Biden's term in office.