A meeting between Sir Keir and Mr Trump would be a significant moment which would be seen as diplomatically savvy, especially if a meeting with Ms Harris materialises. Sir Keir Starmer will travel to Washington this coming week for a bilateral meeting with President Biden. The trip to the White House, on Friday, will be the prime minister's second visit since he was elected in July. In a statement, the White House said the leaders would focus on "global issues of mutual interest". "The leaders will have an in-depth discussion... including continuing robust support to Ukraine in its defence against Russian aggression, securing a hostage release and ceasefire deal to end the war in Gaza, protecting international shipping in the Red Sea from Iranian-backed Houthi threats, and advancing a free and open Indo-Pacific," the White House statement said. It continued: "They will also discuss opportunities to strengthen US-UK cooperation to secure supply chains and increase climate resilience. President Biden will underscore the importance of continuing to strengthen the special relationship between the United States and the United Kingdom." The UK is heavily invested in several live geopolitical challenges which all predate Sir Keir's premiership. The hope, according to sources, is that mutual progress can be made on the various challenges with the outgoing Biden administration.

Britain and the US have cooperated closely on Ukraine, leading a Western alliance that has, at times, shown some reluctance in its continued support against Russian aggression.

On protecting international shipping in the Red Sea against continued Houthi attacks from Yemen, the UK has been a key partner for the US in a mission that's shown limited success.

The potential for some divergence between the two leaders could come over Gaza.

Last week, the UK announced that it would suspend the export of some arms to Israel because of the risk that they could be used in non-compliance with international humanitarian law.

US government lawyers have not come to the same conclusions about how Israel is using weapons in Gaza but this week a State Department spokesman said the UK was making a sovereign decision that it was entirely entitled to make.

Notably, however, a foreign policy advisor to Republican presidential candidate Donald Trump struck a different tone.

Robert O'Brien - who is likely to be in a Trump White House if he wins in November - said that a UK-US special relationship would be under strain if the UK restricted weapons sales to Israel.

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The relationship between Mr Biden and Sir Keir reflects their political alignment. During his first visit to the White House, just days after taking office, President Biden, who was then the Democratic candidate for November's election, spoke warmly of the much coveted "special relationship".

"I kind of see you guys as the knot tying the transatlantic alliance together, the closer you are with Europe. We know where you are, you know where we are," Mr Biden told Sir Keir.