Saudi Arabia's invitation to Qatari emir could presage a thaw in the relationship that has become increasingly tense in recent years.
Saudi King Salman has invited Qatar's emir to a meeting next week of the Gulf regional bloc in Riyadh, Qatari state media said on Tuesday, without specifying if Doha had accepted.
The invitation to the December 10 summit of the six-nation Gulf Cooperation (GCC) comes amid signs of reduced animosity between Qatar and Saudi Arabia, which has led an economic boycott of Doha since 2017.
Saudi Arabia and allies Egypt, Bahrain and the United Arab Emirates closed their airspace to Qatar Airways and banned travel to the country over charges that Doha backs extremists and seeks closer ties with Iran.
Qatar vehemently denies the charges.
The three Gulf boycott countries are currently participating in a regional football tournament in Qatar, having announced their participation at the last minute.
Saudi Arabia, which has also sealed its land border with Qatar, will play the hosts at the semi-finals on Thursday.
"The emir, Sheikh Tamim bin Hamad Al Thani, received a written message from... Saudi King Salman bin Abdulaziz al Saud to attend the (GCC) summit," the Qatar News Agency reported.
The emir has been represented by senior officials at GCC summits since the blockade was imposed, despite having received invitations.
Regional analyst and King's College London assistant professor Andreas Krieg said he believed that Riyadh had pushed for the gathering to be shifted from the UAE to Saudi Arabia to increase the likelihood of the emir attending.
"Talks that have been held over the last couple of weeks, including the ones with the foreign minister, have centred on a lift of the blockade from the Saudi side," he said.
The Qatari Foreign Minister Mohammed bin Abdulrahman Al Thani met with officials in Saudi for talks last month, according to an Arab diplomatic source.
"For the (Qatari) emir to attend will depend on whether the Saudis can keep their side of the bargain, which would be to lift at least the flight ban or open their side of the border," added Krieg.
'The right direction'
Kuwaiti Deputy Foreign Minister Khaled al Jarallah said last month that the boycotting countries' decision to travel to Doha was "a clear indication of the progress towards solving the Gulf crisis".
Other steps were being taken that "affirm we are heading in the right direction to reach positive results", he added, without giving details.
An official from the Cairo-based Arab League is visiting Doha for a conference during the tournament, raising hopes for mediation efforts.
The boycotting countries had refused to participate in the previous Gulf Cup two years ago, which was originally scheduled to be held in Qatar just a few months after the crisis erupted.
But they took part when the tournament was subsequently moved to Kuwait.
Outside of Qatar, there have been glimmers of a possible end-game to the spat which has seen the two sides trade barbs on everything from access to the Muslim holy city of Mecca to alleged Twitter hacking.
Leading Emirati politics professor Abdulkhaleq Abdulla, an authority on the UAE's political thinking tweeted that the end of the boycott could be in sight following the Gulf Cup announcement.
Abdulla called the trio's decision "as political as it is sporting".
The latest signs of progress have emerged despite Doha resolutely refusing to bow to the boycotting countries' demands that it close down its Al-Jazeera broadcaster, downgrade ties with Iran and close a Turkish military base in Qatar.
The regional schism has seen families divided and Qatari businesses face increased costs as well as complicated regional travel and diplomatic efforts.