Qatar joined its neighbours at a summit Tuesday in supporting Egypt under President Abdel Fattah El-Sisi.
In their final statement, leaders of the six-nation Gulf Cooperation Council (GCC) states announced their "full support to Egypt" and the "political programme of President Abdel Fattah El-Sisi".
The ouster of Islamist president Mohamed Morsi strained ties with Qatar, which had been a key Morsi backer.
Qatar had repeatedly denounced ouster of Islamist president Mohamed Morsi, and still provides shelter for many Muslim Brotherhood leaders.
Egypt had already withdrawn its ambassador in February, although Doha has kept its envoy in Cairo.
Saudi King Abdullah last month urged "Egypt, the people and leadership, to seek with us the success of this (reconciliation) move as part of Arab solidarity."
Convening the Doha summit, which had been shortened to one day, was made possible only by last-minute Kuwaiti mediation that succeeded in resolving a dispute between Saudi Arabia, the United Arab Emirates and Bahrain with Qatar over the Muslim Brotherhood.
In an unprecedented development, the three nations had recalled their ambassadors from Doha in protest against Qatar's support for the Islamist movement, branded as a terrorist organisation by Riyadh and Abu Dhabi, and outlawed in Egypt.
Diplomatic staff returned to Qatar last month, paving the way for Tuesday's summit.
Qatari Sheikh Tamim bin Hamad Al-Thani said he hoped the summit would "signal a new beginning for Gulf relations".
He said that "differences in viewpoints" between GCC states should not extend to their populations and even called for taking practical steps to transform the GCC from a loose bloc into a union.
In his opening remarks, Sheikh Tamim called for a joint regional effort to confront "terrorism".
Most GCC states are members of the US-led international coalition fighting militants from the Islamic State group in control of large parts of Iraq and Syria.
Saudi and UAE warplanes have carried out raids on IS targets while Kuwait has provided the coalition with logistical support.
Kuwaiti Emir Sheikh Sabah al-Ahmad Al-Sabah meanwhile called for heightened cooperation to face the sharp drop in oil prices which has "affected our revenues and development programmes".
He urged "strengthening our joint economic efforts" to face "any negative developments that could affect" economies of the six energy-rich nations.
The plummeting price of oil, which makes up around 90 percent of GCC public revenues, has fallen by about 40 percent since June, leaving the six member states facing a potential $300 billion loss in income compared with last year.
Oil prices have extended their losses since OPEC kept its production unchanged last month, under pressure from Gulf members led by Saudi Arabia seeking to defend their market shares.
Only three Gulf leaders attended the summit -- the emirs of Kuwait and Qatar and King Hamad of Bahrain. The other heads of state could not attend for health reasons.
The summit also looked at ways to implement an earlier decision to form a joint military command, based in Riyadh, according to the GCC secretariat.
It also studied the establishment of a naval force to be stationed in Bahrain and a joint police force with its headquarters in the UAE.
*The story was edited by Ahram Online.