Saudi Arabia, the UAE, Egypt and Bahrain all cut off diplomatic contact with Qatar after officially accusing it of "sponsoring terrorism" last week. Qatar has denied the allegations.
On Sunday, Iran had sent five planes of vegetables to Qatar. Turkey and Qatar have developed close ties over the years and reached agreement in 2014 to set up a Turkish military base there. Both have delivered food supplies to the country and Turkey has agreed to deploy troops.
"This is the time to work for Qatar", said Moutaz Al Khayyat, chairman of Power International Holding, who bought the 1,300-pound beasts in the USA and Australia.
Saudi Arabia, Bahrain, the UAE and Egypt had earlier severed diplomatic ties and transport links with Qatar, accusing it of supporting "extremism".
"Without the support of Turkey and Qatar it would not be possible for Syria to push back Daesh (IS)", Erdogan said, referring to Ankara and Doha's backing of some of the same Syrian rebel groups. A United Kingdom government report also identified Saudi Arabia as a key sponsor of groups involved in radicalizing young Britons. Saudi Arabia has also closed off Qatar's sole land border.
Saudi Arabia's state news agency reported few details about the call on Tuesday, only saying the two leaders discussed bilateral relations and counterterrorism efforts.
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Earlier, German Finance Minister Wolfgang Schaeuble made very similar comments on the possibility of Britain staying in the EU. The Prime Minister triggered Article 50, the legal process for leaving the European Union , on 29 March.
He did, however, caution that Qatar's would not abandon its independent foreign policy just because the other nations in the GCC don't like some of their decisions.
Meanwhile, the United Arab Emirates has declared they will withdraw all money from Qatar Banks immediately, over Qatar's alleged support of terrorism.
The summit included one bilateral meeting between the USA and Saudi Arabia and two multilateral meetings, one between the members of the Gulf Cooperation Council and the other with Arab and Muslim countries.
"A very grave mistake is being made in Qatar, isolating a nation in all areas is inhumane and against Islamic values". Oman has stayed out of the conflict.
Before 2011, not many in the West took notice of Qatar - a tiny state with the world's biggest per-capita-GDP.
Erdogan added he would hold three-way phone talks on the crisis later Tuesday with French President Emmanuel Macron and Qatar's ruler Emir Sheikh Tamim bin Hamad al-Thani.