The Turkish president urged Qatar and the quartet of Arab countries isolating Doha to negotiate and end the crisis on Monday as his two-day trip to meet with both sides ended in talks with the Qatari emir.

Turkey backs the Kuwait-led mediation efforts to end the crisis and hopes both sides can find a resolution through dialogue, a spokesman for president Recep Tayyip Erdogan said on Monday.

"Moreover, the importance of acting in unity for the Muslim countries and respecting each other's sovereignty was highlighted," added Ibrahim Kalin.

There appears to have been some momentum for de-escalation and potential direct talks after US secretary of state Rex Tillerson called on the countries boycotting Qatar to open the land border with Saudi Arabia as a sign of good faith. It comes after steps taken by Doha to implement a new bilateral agreement with Washington on countering fund-raising for terrorist groups.

In his first remarks on the crisis since it began early last month, Qatar's emir, Sheikh Tamim Al Thani, said on Friday last week that he is willing to negotiate as long as Doha’s sovereignty is not violated.

Mr Erdogan arrived in the Qatari capital on Monday and was greeted by Sheikh Tamim at his aeroplane, ahead of talks on the Gulf crisis. His visit to Qatar followed shuttle diplomacy between those involved in the dispute in recent weeks by vice president of the EU Commission, Federica Mogherini, along with Mr Tillerson and the foreign ministers of Britain, France and Germany.

The Turkish president met with Saudi Arabia’s King Salman and Crown Prince Mohammed bin Salman in Jeddah on Sunday for talks he said were aimed at helping to find a resolution to the Qatar crisis.

Mr Erdogan, who was accompanied on his Gulf trip by key cabinet ministers, flew to Doha from Kuwait, where he met officials in the country mediating the conflict.

The UAE and Saudi Arabia — which, along with Bahrain and Egypt, began boycotting Qatar last month — are two of Ankara’s increasingly important economic partners. But Qatar is also Turkey's closest strategic partner in the region, and Ankara has been instrumental in aiding Doha during the boycott.

Before embarking on his trip, Mr Erdogan said on Friday that “political problems are temporary, whereas economic ties are permanent and I expect the investors from the Gulf countries to choose long-term ties.”

No statements were made after the Turkish president's meetings in Jeddah and few expected them to lead to any breakthroughs. In Qatar, however, Mr Erdogan was not only greeted personally at his plane by the emir but Qatari special forces were deployed to personally guard him. It comes after a failed coup to depose the Turkish president in July last year.

Ankara sped up troop deployments to its new base near Doha during the early stages of the crisis when Sheikh Tamim was under acute pressure, and has also sent hundreds of air shipments of food and other commodities to make up for the loss of the country's largest-volume trade links.

The quartet initially demanded that Qatar close the Turkish base, and Ankara's recently improved ties with the UAE and Saudi Arabia have again been severely tested by Turkey’s full backing of Doha during the crisis.

*With additional reporting from Reuters