John Kerry, the US secretary of state, has arrived in Doha to meet with members of the Gulf Cooperation Council (GCC) to reassure them over last month's nuclear deal between world powers and Iran.
Kerry is expected to hold a series of meetings on Monday with tops officials of Qatar, as well as foreign ministers from the GCC.
Ahead of his arrival, foreign ministers of the GCC held a preparatory meeting in Doha on Sunday.
Kerry said he would be travelling to Doha to make the case to members of the GCC that the nuclear agreement forged with Iran would make the Middle East more secure.
The Gulf Arab states have publicly welcomed the deal reached last month in Vienna but many have expressed private reservations.
Al Jazeera's Hashem Ahelbarra, reporting from Doha, said that GCC officials are expected to "voice their concerns with the Iran deal."
"This is quite a delicate moment for the Gulf countries," he said. "They are worried that Iran might finally be able to foster ties with the West, get the sanctions lifted and pursue an active role in the region."
Kerry is also expected to discuss the fight against the Islamic State of Iraq and the Levant (ISIL) in Syria and Iraq.
Russian Foreign Minister Sergei Lavrov also arrived separately in Doha on Sunday night with plans to hold a three-way meeting with his Saudi Arabian counterpart and Kerry on Monday morning.
The Russian foreign ministry said Lavrov was visiting Qatar to discuss peace moves in Syria, Yemen and Libya, international consolidation against ISIL, stability in the Gulf, and bilateral relations between Russia and Qatar.
Earlier on Sunday, Kerry stopped in Cairo for meetings with his Egyptian counterpart Samed Shoukry and Egyptian President Abdel Fattah el-Sisi where he said US-Egyptian relations were returning to a "stronger base" in bilateral ties despite tensions and human rights concerns.
The development comes two days after the US delivered eight F-16 fighter jets to Egypt as part of a military support package.
In talks with Shoukry, Kerry said the US would "continue to provide robust training to the Egyptian military, as the military seeks it and desires it, in an effort to build capacity, and also to meet the highest expectations of your military for its professionalism".
He noted that in addition to the F-16s, the US had provided Egypt with Apache helicopters, attack boats, armoured vehicles and other weapons systems this year. More is on the way, he said.
At the same time, he acknowledged stress in the US-Egypt relationship over human rights and said the US would continue to press Egypt on the arrests of dissidents and journalists and mass trials.
Source: Al Jazeera and agencies