Saudi Arabia, the United Arab Emirates (UAE) and several other Sunni-majority countries have severed relations with Qatar since June 5, accusing the Gulf state of supporting terrorism based on its ties with the Muslim Brotherhood, Hamas and the Taliban.
Another point of departure is Qatar's ties with Iran, with whom it shares one of the world's biggest gas fields.
Qatar has denied the accusations and called the collective decision "unjustified." Kuwait, Turkey and the US have all urged a political solution as the bloc isolates Qatar using various ad hoc sanctions, including shutting down their airspace to Qataris and blocking import routes.
The dispute began in May when Qatar's Emir Sheikh Tamim bin Hamad al Thani was reported to have made statements on the state news agency supporting Iran. Doha said the statements were fabricated and disseminated via a hack.
Here are the latest developments in the crisis:
July 25, Tuesday
Erdogan says Gulf trip 'productive'
Turkey's President Erdogan on Tuesday described his trip to the Gulf to deal with the Qatar crisis as "productive and successful".
"The visits on the Gulf tour were productive and successful," Erdogan told lawmakers from his ruling AK Party at a parliamentary meeting.
"The contacts we have made during this visit have been useful, and we will continue our efforts for the stability and peace of the region with increasing determination."
Saudi-led bloc blacklists Qatari, Yemeni groups
Saudi Arabia and its allies announced they have blacklisted charity groups and individuals with ties to Yemen, Qatar and Libya, labelling them "terrorist" over alleged ties to extremism.
Saudi Arabia, the United Arab Emirates, Bahrain and Egypt released a joint statement proscribing nine charity organisations and nine individuals it said were "directly or indirectly linked to Qatari authorities."
Three organisations in Yemen and six based in Libya were accused of ties to Al Qaeda and a Syrian affiliate of the group in Tuesday's statement.
The statement also said three Qatari nationals, three Yemenis, two Libyans and a Kuwaiti citizen were involved in "fundraising campaigns to support Jabhat al Nusra and other terrorist militias in Syria."
July 24, Monday
Erdogan ends Gulf tour saying progress made, but solution will take time
Turkey's President Recep Tayyip Erdogan left Qatar on Monday after two days of visiting Gulf countries trying to mediate the worst row among Arab states for years.
"I think that our visit and contacts [in the region] have been an important step on the way to rebuilding stability and mutual confidence," he told reporters at Ankara airport after returning from Qatar.
But he cautioned, "Of course it's easy to demolish something. What is hard is to again rebuild something that has been demolished."
Turkey has been Qatar's most powerful ally in the dispute, rushing through legislation to send more troops to its base in Doha as a sign of support.
Kuwaiti and Western efforts to end the crisis have yielded little so far. The four Arab states want Qatar to reduce ties with their arch-foe Iran, close down the Turkish military base and shut down Qatar's Al Jazeera TV channel, which they view as critical of their governments.
Egypt's Sisi vows to keep up Qatar blockade
Egypt's President Abdel Fattah el Sisi on Monday said his government would keep up a blockade of Qatar over charges it supports terrorism, in defiance of international efforts to end the crisis.
"Egypt will stand by its decision and will not backtrack on this matter," Sisi said at a youth conference in Alexandria.
"Our persistence on its own, our stance and this bloc, is pressure in itself."
Russia ready to mediate in Qatar row if asked
Russia is ready to help mediate the dispute if approached, Foreign Minister Sergei Lavrov said in an interview released on Monday.
"We are interested in this crisis being overcome, taking into account mutual concerns and finding solutions which will be acceptable for all participants of this process," Lavrov told Kurdish television channel Rudaw.
"We support the mediating efforts which are being made by the Emir of Kuwait. If as part of those efforts or in addition to them all sides think that Russia could also do something useful, we will be ready to respond to such appeals," Lavrov said.
For more on earlier developments click here.