The Defence Secretary has used his visit to Washington DC to help bolster another type of special relationship – between the Royal Marines and the United States Marine Corps.
John Healey attended an event at the British Embassy in the US capital to celebrate the USMC's 250th anniversary.
The USMC was founded on 10 November 1775, in Philadelphia, Pennsylvania, since when the Marines have fought from the shores of Tripoli to the valleys of Afghanistan.
Although the official anniversary doesn't take place until later in the year, the celebrations have already begun, with a 250th birthday cake being baked for the occasion, featuring the corps' cap badge of an eagle atop a globe and anchor.
The news was announced in a post by the MOD on X that read: "The USMC and Royal Marines have been training and fighting together for over a century.
"Defence Secretary John Healey MP joined 🇺🇸 and GB personnel at the British Embassy in Washington to congratulate the US Marines in their 250th year.
"Per Mare Per Terram and Semper Fidelis!"
Per Mare Per Terram is the motto of the Royal Marines and the Latin translates to By Sea, By Land, symbolising the Royal Marines' dual role of fighting both on board ships and on dry land.
Semper Fidelis, another Latin phrase, is the US Marine Corps' motto. It means Always Loyal, and is often shortened to Semper Fi.
The aim of Mr Healey's visit to the United States is to strengthen the depth of the UK-US relationship, bolstering security and supporting economic growth.
His talks with his US counterpart, Pete Hegseth, also aim to help secure a lasting peace in Ukraine and strengthening the bonds between Nato allies.