The announcement was made during a meeting between the new British Prime Minister, Keir Starmer, and Volodymyr Zelenskyy at the NATO summit in Washington, DC, on Wednesday.

The decision to authorize the use of Storm Shadow missiles, welcomed by Ukraine, marks a hawkish shift from the previous Conservative government's policy. John Healey, the new Defence Secretary, signaled the move but declined to discuss "operational arrangements." He told Sky News that Britain would do everything possible to support Ukraine in repelling Putin's invasion.

In Washington, Mr. Healey stated, "We provide weapons and equipment where we can to help them defend themselves. As with any nation in conflict, we require that war is conducted according to the rules of the Geneva Convention, as mandated by international law."

However, Russian President Vladimir Putin's spokesman, Dmitry Peskov, responded to the news by stating, "If this is so then, of course, this is another absolutely irresponsible step towards escalating tensions and seriously escalating the situation." He told Reuters, "We will be watching this very thoroughly and respond accordingly."

The significant announcement was a key aspect of a NATO summit with multiple distinct focuses. The summit, which brought together leaders from the 32-member states, concludes on Thursday and marks the 75th anniversary of the defense alliance.

In a lengthy declaration, the alliance's members announced that Ukraine is on an "irreversible" path to NATO membership. This wording is important to the Ukrainian government but is likely to agitate Moscow.

"We fully support Ukraine's right to choose its own security arrangements and decide its own future, free from outside interference. Ukraine's future is in NATO," the declaration stated.

It continued: "As Ukraine continues this vital work, we will continue to support it on its irreversible path to full Euro-Atlantic integration, including NATO membership. We reaffirm that we will be in a position to extend an invitation to Ukraine to join the alliance when allies agree and conditions are met."

Defence Secretary John Healey emphasized that the UK should be "the leading European nation in NATO" and must take a leading role in supporting Ukraine.

In a rare signal of political continuity regarding the supply of weapons to Ukraine, he said: "The Sunak pledge comes with the Starmer guarantee of delivery."

When asked about the prospect of a second Donald Trump presidency, Defence Secretary John Healey made cautiously measured remarks, suggesting that more "heavy lifting" could be required.

"Whoever is elected to the White House, we must acknowledge that American priorities are likely to increasingly focus on the Indo-Pacific region and other parts of the globe," he stated.

"As a consequence, European nations within NATO must take on more responsibility and leadership roles that we traditionally relied on the Americans to fulfill."

Behind closed doors, European diplomats based in Washington express more candid views, suggesting that NATO's current gradual rebalancing of power could potentially shift dramatically away from US dominance if Donald Trump were to secure a second term.

The NATO summit has been overshadowed by concerns surrounding President Biden's agility and perceived cognitive decline. Calls from his friend and megadonor George Clooney for Biden to step aside as a candidate have added significant pressure.

Today, Senate Democrats will have a lunch meeting with key Biden advisers Mike Donilon and Steve Ricchetti, along with Biden-Harris campaign chair Jen O'Malley Dillon.

Hours before the president's rare news conference to conclude the NATO summit, anticipation builds as it represents a significant opportunity for him to demonstrate his capability once more.

During his meeting with Prime Minister Starmer in the Oval Office, the president appeared tired but managed to navigate the meeting without any notable slip-ups. This encounter marked the midpoint of Sir Keir's successful visit to Washington, described by UK diplomatic sources as highly successful.

The timing was fortuitous for the three top ministers of the new British administration to meet many of their counterparts in one location during the first week of their government. Sir Keir, along with Foreign Secretary David Lammy and Defence Secretary John Healey, frequently appeared together as a trio. They visited Capitol Hill, where they engaged with leaders from both sides of the political spectrum.