Just two months after the State Department approved the sale, Ukraine has reported the receipt of their first FGM-148 Javelin anti-tank missiles from the United States. President Poroshenko confirmed the “long-awaited weapons” have arrived.

The $47 million deal for Raytheon and Lockheed Martin, involves 37 Javelin Command Launch Units and 210 missiles. The Poroshenko government says the missiles will be used to “protect Ukrainian soldiers.”

There are substantial concerns, however, that the US arms are going to threaten the ceasefire in Eastern Ukraine. With better arms, Ukriane’s military may believe they can more readily take on rebels in the area who have looted some tanks and other armored vehicles.

Concern about arms sales restarting the war in the east is a big part of why Russia opposed the sale. East Ukraine’s rebels are ethnic Russians, and many in the Ukrainian government have presented the fight against those rebels as the start of a war against Russia.

Most nations are avoiding the sale of deadly arms to Ukraine specifically over concern it would destabilize the region. The US, however, was never particularly supportive of the eastern ceasefire, and has been eager to sell new arms to Ukraine as part of a general anti-Russia push in the region.