The Gulf countries on Monday night welcomed the nuclear deal reached between Iran and world powers, but expressed concerns that the deal would allow greater regional interference by the Islamic republic.

Speaking for the six-member Gulf Cooperation Council (GCC), Qatari Foreign Minister Khalid bin Mohammad Al-Attiyah said there was support for the nuclear deal among countries in the Gulf.

"This was the best option among other options to come up with a solution to the nuclear weapons of Iran through dialogue," Qatar's top diplomat said.

The GCC groups Qatar with Bahrain, Kuwait, Oman, Saudi Arabia and the United Arab Emirates.

Following talks with foreign ministers of the GCC, U.S. Secretary of State John Kerry said Washington has agreed to speed up arms sales to the Gulf countries.

Kerry said the U.S. and the region's Arab states would also step up efforts to share intelligence and increase the number of joint military exercises.

During his visit to the Qatari capital, Kerry also met with Russian Foreign Minister Sergey Lavrov to discuss Syria and other regional issues.