The Salwa border crossing has been closed since June 5 when Saudi Arabia, Egypt, Bahrain and the United Arab Emirates severed diplomatic and trade ties with Qatar over accusations the emirate fostered Islamist extremists. Qatar has denied the allegation.

The announcement to reopen the frontier for Qatari pilgrims came after powerful Saudi Crown Prince Mohammed bin Salman received an envoy from Doha, the official Saudi Press Agency said, in the first public high-level encounter between the nations since the crisis erupted.

King Salman has allowed "the entry of Qatari pilgrims to the Kingdom of Saudi Arabia through Salwa border crossing to perform hajj, and to allow all Qatari nationals who wish to enter for hajj without electronic permits", a statement on SPA said.

He also ordered that private jets belonging to Saudi airlines be sent to Doha airport "to bring all Qatari pilgrims at his expense".

The decision also came after Prince Mohammed received a phone call from US Secretary of State Rex Tillerson, who has sought repeatedly to defuse the regional crisis, SPA reported, without revealing the details of the conversation.