KUWAIT CITY: US Secretary of State John Kerry has called Qatar's young new emir and voiced hope for further cooperation with the increasingly active nation, an official said Wednesday.

Kerry, who is on a regional tour aimed at coordinating support for Syria's rebels, spoke by telephone Tuesday with the new emir, 33-year-old Sheikh Tamim bin Hamad al-Thani, and his father Sheikh Hamad bin Khalifa al-Thani.

Kerry said "he looks forward to working with Sheikh Tamim as our two countries promote regional and global stability, prosperity and progress," said a US official who was accompanying Kerry in his latest stop Kuwait.

"He reaffirmed that the United States will continue to stand by Qatar as a valued partner," he said.

The emir, who had been in power for 18 years, abdicated Tuesday just two days after he received Kerry at his palace. Kerry also met with Sheikh Tamim, referring to him as the "heir apparent" of the gas-rich kingdom.