Minister of State for Foreign Affairs for the United Arab Emirates, Anwar Gargash, speaks at an event at Chatham House in London, Britain July 17, 2017. REUTERS/Neil Hall

DUBAI (Reuters) - The United Arab Emirates, one of four Arab countries that have imposed sanctions on Qatar, said on Saturday that Doha needed to change its policies before a dialogue could take place.

Saudi Arabia, the UAE, Bahrain and Egypt cut ties with Qatar and imposed an economic boycott last month, accusing it of financing extremist groups and supporting terrorism, charges Doha has repeatedly denied.

UAE Minister of State for Foreign Affairs Anwar Gargash said a call for dialogue by Qatar’s emir Sheikh Tamin bin Hamad al-Thani was welcome, but this could only happen after Doha had made changes.

He did not specify these, but the four countries involved have issued more than a dozen demands, telling Qatar to close down Al Jazeera television, curb relations with Iran and shut down a Turkish military base.

“Dialogue is necessary and needed but its backbone has to be revision,” Gargash said on his Twitter account.

He expressed disappointment with a speech by Sheikh Tamim on Friday, the first the emir had given since the start of the crisis.

“I had hoped that the speech of Sheikh Tamim would be an initiative for revision,” Gargash said.

Turkish President Tayyip Erdogan, an ally of Qatar, will visit Saudia Arabia, Kuwait and Qatar during a two-day mediation trip that begins on Sunday.