Qatar has announced it will be spending $3.71bn (€3bn) to buy 28 military helicopters, its latest high-profile defence purchase during a bitter diplomatic crisis with its Gulf neighbours.

The deal for the NH90 helicopters was announced on Wednesday by Qatar's defence ministry at a military hardware conference in Doha.

Mashout Faisal Al Hajri, commander of the Emiri Air Force helicopter wing, said the deal "will contribute greatly to enhancing the capabilities and efficiency" of Qatar's air force, according to Qatar News Agency.

Italian defence contractor Leonardo will act as the main contractor in the deal, although it was officially signed with the NHI consortium, which also includes Airbus and Dutch aircraft manufacturer Fokker.

"We are proud to have signed this contract that expands and continues Leonardo's strong and long-term partnership with Qatar," said Alessandro Profumo, Leonardo's chief executive.

He said the delivery of the helicopters should begin in 2022.

Also on Wednesday, Qatar announced it had signed a memorandum of understanding with United States defence contractor Raytheon covering the area of cybersecurity.

Gulf crisis

Qatar has been isolated by a group of neighbouring countries and former allies led by Saudi Arabia for the past nine months in a political, diplomatic and economic dispute.

Qatari defence minister, Khalid bin Mohammad al-Attiyah, has said the bloc of countries opposed to Qatar has considered an invasion of the World Cup 2022 host.

Since the Gulf political crisis started, Qatar has spent some $30bn (€25bn) on military hardware.

Among the purchases are F-15 planes from the US, a Rafale fighter jet deal with France and another for Typhoon aircraft from Britain.