The U.S. is close to an agreement to give Ukraine long-range cruise missiles that could reach deep into Russia, but Kyiv would need to wait several months as the U.S. works through technical issues ahead of any shipment, U.S. officials said.

The inclusion of Joint Air-to-Surface Standoff Missiles (JASSM) in a weapons package is expected to be announced this autumn, three sources said, though a final decision has not been made. The sources declined to be named because they are not authorized to discuss the topic.

Sending JASSMs to Ukraine could significantly alter the strategic landscape of the conflict by putting more of Russia in range of powerful, precision-guided munitions, an important concern of the Biden administration, the officials said.

Military analysts have suggested the introduction of JASSMs - which are stealthy and can strike further than most other missiles in Ukraine's current inventory - could push Russian staging areas and supply depots back by hundreds of miles.

This would severely complicate Russia's ability to sustain its offensive operations and potentially provide Ukraine with a strategic advantage.

Launching them from points near Ukraine's northern border with Russia could allow them to hit military installations as far away as the Russian cities of Voronezh and Bryansk. In the south, dropping them near the front lines could enable strikes on airfields or naval facilities in Crimea.