On July 1, some sources familiar with the matter revealed that the Pentagon decided to suspend the aid of many types of missiles to Ukraine because they feared that the amount of ammunition in the US arsenal was in an alarming situation.
The decision was driven by Pentagon policy officer Elbridge Colby, after he reassessed the stockpile of artillery shells, anti-aircraft missiles and precision guided- missile launchers.
White House Press Secretary Anna Kelly said the move was based on the America First criteria in the context that Washington is also supplying weapons to many other countries.
Among the military equipment that was stopped for aid were missiles for patriot air defense systems, precision artillery shells, Hellfire missiles and other missiles used by Ukraine on its F-16 fighter jets and unmanned aerial vehicles (UAVs).
Another source quoted US Secretary of Defense Pete Hegseth as saying that the delay in ammunition aid to Ukraine, which was pledged by former President Joe Biden, will last for several weeks.

The Pentagon's decision to suspend some shipments has worried pro-Ukrainian politicians in the US Congress. They said Kiev would be more vulnerable to Russian airstrikes.
Lawmaker Marcy Kaptur affirmed that the Ukrainian army will suffer heavy losses when the US stops providing "effective" weapons, including air defense systems and patriot missiles.
Member Kaptur said the above weapons are the focus of Ukraines defense.
Another source said that the status of these ammunition has actually been assessed by the Pentagon since February on concerns that the Department of Defense is spending too much on military operations in the Middle East.
The Pentagon later drafted a memorandum of understanding to Secretary Pete Hegseth to freeze some of the rarest ammunition in US reserves to Ukraine, the source said.
However, this proposal was delayed on Mr. Hegseth's table for many months as the Ministry of National Defense had to undergo a series of personnel changes.
Plans have been made to redirect key ammunition, including artillery shells, tank shells and air defense systems, back to US or Israeli territory.