UK awaiting US approval to allow Kiev attack Russia

However, a source within the UK government said the request was submitted to the system over a month ago, but there has been no response yet.

The source mentioned that, as far as they understand, the issue is effectively "stuck in their system." A second source within the UK government confirmed that "discussions were still ongoing around Storm Shadow with allies" and a third defence source described it as a "routine US process".

It is understood that while the UK wants to give Ukraine the freedom to use long-range weapons as it sees fit, this requires consensus from allies, including the US, France, and a third unnamed NATO country. A government source emphasised that the UK does not blame the US for the delay, adding that such policy changes take time.

The Storm Shadows have a range of 250 kilometres and can be used to strike military bases deep within Russia, which play a crucial role in Moscow's military actions in Ukraine.

Sabrina Singh, Deputy Spokesperson for the Pentagon, acknowledged during a briefing that the US is "concerned about escalation" when it comes to Ukraine's use of long-range weapons. 

She also suggested that long-range weaponry may not be necessary to help Ukraine liberate its territory.

Matthew Palmer, the Deputy Chief of Mission at Embassy London, distanced himself from the notion that the US has any say in the matter during an interview with Times Radio set to air on Sunday. He stated that the conditions under which British weapons may be used are a matter for London and Kyiv to decide.

Among British military personnel, there is a theory that the US may be waiting to assess the impact or consequences of a Ukrainian operation in Russia before making a decision, although they have stated they expect a quick resolution of the issue.