According to two US officials and another source familiar with the document, Russia publicly protested the US’ continuous shipping of weaponry to Ukraine this week, writing a diplomatic note to the State Department warning of “unpredictable consequences” if the support continues.

The note, known as a demarche, was issued earlier this week, just as the US was set to unveil a new $800 million military aid package to Ukraine. The document was initially reported on by the Washington Post.

For the first time, the US has agreed to equip Kyiv with high-power capabilities that some Biden administration officials saw as too high an escalation risk only a few weeks ago, including 11 Mi-17 helicopters, 18 155 mm Howitzer artillery, and 300 additional Switchblade drones.

It was expected that Moscow would protest the supplies, according to a source familiar with the Russian diplomatic statement, but it was unclear whether this meant Russia would adjust its behavior in any manner. However, as the war continues on, this person recognized that the memo could signal a more aggressive Russian posture against the US and NATO.

The US believes Russian President Vladimir Putin’s risk tolerance has increased, and that he may be inclined to take more aggressive measures against the US in retaliation to its backing for Ukraine, according to CNN.

Asked for comment, a separate US official said, “We won’t confirm any private diplomatic correspondence. What we can confirm is that, along with Allies and partners, we are providing Ukraine with billions of dollars worth of security assistance, which our Ukrainian partners are using to extraordinary effect to defend their country against Russia’s unprovoked aggression and horrific acts of violence.”