"The President of the Republic has just spoken with President Trump, recalling the good historical relationship between the two countries, which is a guarantee of the continuation of a useful cooperation in the future," a presidential aide said.

According to the official, the conversation lasted "about 12 minutes", during which, among other subjects, "they talked about the Lajes base" in the Azores and de Sousa reminded the president-elect "that Portugal was the first country to recognise the independence of the United States of America."

Trump won the presidential elections on 8 November as the Republican Party candidate, beating his Democratic Party rival, Hillary Clinton, and is to take office as head of state on 20 January, succeeding Barack Obama.

On the day after the elections, 9 November, de Sousa said he hoped that the next president would “carry forward a great history and a great democracy", and also the “magnificent friendship” with Portugal, taking into due consideration the weight of the Portuguese community in the US.

On 7 December de Sousa raised the subject once more, at a conference in Lisbon with the theme "Portugal and the United States of America: Partners in a World in Change". On that occasion, in the presence of the US ambassador to Portugal, de Sousa stressed the importance of the mid-Atlantic Azores as the "first door to Europe", stating that "geography does not change", and arguing for a strengthening of relations between Portugal and the US.

The US has announced its intention of scaling back the air force presence at the Lajes base, which is a major local employer in a region that is one of Europe's poorest.