DOHA, May 25 (Reuters) - Qatar on Thursday played down fears of a rift with fellow Gulf Arab states over what it said were fake remarks by its emir criticising U.S. foreign policy, saying they shared the same interests and fate.

"Qatar is always in favour of maintaining strong and brotherly relations with GCC (Gulf Cooperation Council)countries," Foreign Minister Sheikh Mohammed bin Abdulrahman al-Thani told a new conference in the Qatari capital.

"In Riyadh we had very positive discussions about the relationship between Gulf countries," he added, referring to talks in the Saudi capital last week during a visit by U.S. President Donald Trump.

Qatar's official news agency reported on Tuesday that Sheikh Tamim bin Hamad al-Thani criticised renewed tensions with Tehran, expressed understanding for the Palestinian Hamas movement and Tehran's ally Hezbollah and suggested Trump might not last long in power.

Doha issued a robust denial that the remarks had ever been made and said the news agency had been hacked.

But Gulf Arab countries including oil giant Saudi Arabia permitted their state-backed media to run them throughout the day on Wednesday, quoting Qatar's official news agency.

Sheikh Mohammed reiterated that the emir had made no such remarks and vowed that investigators assigned to look into the hacking would issue a transparent report. He expressed surprise that Gulf media had continued to report the comments attributed to Sheikh Tamim despite the denial.

He said that Qatar had been facing a media campaign in recent weeks, a reference to numerous articles in Western media suggesting Doha tolerates its own citizens sending funds to armed Islamist groups like al Qaeda and Islamic State.

"It is clear that there is a media campaign targeting Qatar and we will confront it, God willing," Sheikh Mohammed said, citing 15 such article in U.S. media in the past five weeks.

He said no Gulf Arab country has contacted Doha about the Emir's purported remarks, and Qatar sought good ties with all Gulf Arab states.

(Reporting by Tom Finn, Writing by Sami Aboudi, Editing by William Maclean and Ed Osmond) ((Sami.Aboudi@thomsonreuters.com; +97143918301;))