Leaders of the six-nation Gulf Cooperation Council (GCC) states, in their final statement, announced their "full support to Egypt" and the "political programme of President Abdel Fattah al-Sisi".
"We believe that a strong Egypt is in the interest of all Arabs and especially for GCC states," Qatari Foreign Minister Khalid al-Attiyah told a press conference at the end of the summit.
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 (UAE) and Bahrain with Qatar over the 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.
Qatar had repeatedly denounced Sisi's ouster of Islamist president Mohamed Morsi, and still provides shelter for many Brotherhood leaders, especially those who have been forced to flee a crackdown in Egypt.
Diplomatic staff returned to Qatar last month, paving the way for Tuesday's summit.
Qatari Emir Sheikh Tamim bin Hamad Al-Thani said he hoped the summit would "signal a new beginning for Gulf relations".
JOINT EFFORT ON 'TERRORISM'
The GCC leaders reiterated their resolve to combat terrorism and welcomed a UN Security Council resolution condemning human rights abuses in Iraq and Syria by the Islamic State (IS) group and Al-Qaeda's Al-Nusra Front.
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"The leaders have reaffirmed the GCC positions of deploring terrorism and extremism in all forms, regardless of its reasons and justifications or source," the final statement said.
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 IS jihadists 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.
On Iran, the GCC states welcomed nuclear talks between the Islamic republic and Western powers on Tehran's nuclear programme and hoped it will lead to a solution.
They also stressed the importance of GCC-Iran ties which should be based on non-interference in internal affairs and refraining from the use of force.
Turning to the unrest in neighbouring Yemen, the leaders urged Shiite Huthi rebels to withdraw from Sanaa and other towns they have overrun since September.
On the economy, Kuwaiti Emir Sheikh Sabah al-Ahmad Al-Sabah called for heightened cooperation to face the sharp drop in world 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.
The Gulf leaders also called for clearing the last hurdles for implementing a long-delayed customs union, common market and unified railway project in 2018.
Only three Gulf leaders attended the summit -- the emirs of Kuwait and Qatar and King Hamad of Bahrain. The other heads of state stayed away for health reasons.