Qatar's emir, Sheikh Tamim bin Hamad Al-Thani, will not attend the Gulf summit in Riyadh, state media reported Tuesday, dampening hopes of a reconciliation between Doha and a Saudi-led bloc.

Saudi Arabia, the United Arab Emirates, Bahrain and Egypt cut all diplomatic and transport ties with Qatar in June 2017 over allegations it backs radical Islamists and seeks closer ties with Saudi arch rival Tehran.

Qatar vehemently denies the allegations.

The emir named Prime Minister Abdullah bin Nasser bin Khalifa Al-Thani to lead the Qatari delegation to Tuesday's summit of the Gulf Cooperation Council (GCC), the official QNA said.

Hopes of reconciliation were high after signs of a thaw between Qatar and its former allies.

Saudi King Salman's invitation to the Qatari emir had raised hopes of a thaw in the bitter two-year-old rift between their governments
Saudi King Salman's invitation to the Qatari emir had raised hopes of a thaw in the bitter two-year-old rift between their governments Saudi Royal Palace / Bandar AL-JALOUD

Following Saudi King Salman's invitation to the emir, Qatar's foreign minister said there had been "some progress" in talks with Riyadh.

Some observers had said that the summit could pave the way for a "reconciliation conference".

Others remained sceptical, saying he was only following protocol and had invited the Qatari leader to last year's summit as well.

Qatar's prime minister attended a series of talks in Saudi Arabia in May, one of the first high-level contacts of the two-year boycott.

Even before the Saudi-led blockade, relations had been rocky, in part because of Qatar-based broadcaster Al Jazeera's critical coverage of the region's affairs and Doha's support for the Arab Spring uprisings of 2011.

The rift has seen the two sides trade barbs on everything from access to the Muslim holy city of Mecca to alleged Twitter hacking.