A letter from Morocco’s King Mohammed VI has confirmed that the country has named a major highway after US President Donald Trump.

Last week, in a social media post, Trump thanked the king for the honour, but there was not a parallel announcement from the Moroccan authorities.

But Morocco’s state press agency has published a letter the king wrote to the president telling him that the name-change was taking place as “a personal expression of my high regard”.

Formerly the Tiznit-Dakhla highway, the road enters Western Sahara, most of which Morocco occupies and claims sovereignty over. But part is controlled by the Polisario Front, an armed group seeking independence for the local Sahrawi people.

In 2020, during the first Trump administration, the US recognised Morocco’s claim over the disputed region as part of a deal whereby Morocco agreed to normalise relations with Israel.

In his letter, dated 2 July but published over the weekend, King Mohammed highlighted what he called the US president’s “historic recognition… of Morocco’s sovereignty over its Sahara” saying that it would “forever be etched in the memory of Moroccans, from generation to generation”.

“Although our relations have always been rooted in close friendship and constant loyalty, they have never been as vigorous and fruitful as during your two presidential terms,” the king added.

The monarch called the 1,055km (655 mile) highway a “strategic axis” linking “north and south of Morocco”. Morocco calls Western Sahara its “southern provinces”.

A former Spanish colony, Western Sahara – which is considered a “non-self-governing territory” by the UN – has been fought over for five decades in one of Africa’s longest conflicts.

The UN has consistently pushed for a solution to the dispute, including a referendum, but the indigenous people of the area have never been able to vote for their own future.

The African Union recognises Western Sahara’s independence.

European governments have until recently avoided taking sides. But some, including the UK and Spain have backed Morocco’s plan to grant Western Sahara autonomy but deny it independence.

Trump’s Truth Social post on the renaming last week also included a video about the road saying that it cost nearly $1bn (£740m) to build.

“I look forward to traveling the entire length of this great highway someday, hopefully soon!” the president wrote.