"Another 150 LTV 2200 ventilators... will be shipped on Saturday", O'Connor said on Wednesday.
Last week, a military transport aircraft delivered the first 50 ventilators from the United States to Russia. In total, Washington will donate Moscow equipment and components worth $5.6 million.
Russia has also provided equipment to the US for fighting the pandemic. The United States purchased medical supplies from Russia, including ventilators and personal protection equipment, after the 30 March telephone call between US President Donald Trump and Russian President Vladimir Putin.
As of 27 May, Russia has confirmed more than 370,000 novel coronavirus cases and around 4,000 fatalities related to the disease, according to the National Health Ministry. The number of COVID-19 cases in the US has reached 1,678,000, with at least 99,000 fatalities registered, the US centres for Disease Control and Prevention data shows.