Qatar's foreign minister said on Monday there was general international agreement with Russia on its call to fight Islamic State, but cautioned that it failed to tackle the root cause of the crisis in Syria, which was President Bashar al-Assad.
In an interview with Reuters, Khaled al-Attiyah also said it was time for Gulf Arab states and Iran to hold "serious dialogue" and discuss all issues to normalize ties.
"Nobody can reject Mr. Putin's call for an alliance against terrorism, but ... we need to treat the cause," he said. "We believe strongly that the Syrian regime, namely Bashar al-Assad, is the real cause."
Qatar is among Sunni Arab countries that have joined in or supported U.S.-led air strikes against Islamic State targets in Syria. However, it has questioned the lack of action by Western powers against Assad's government.
"We can't come together and say, 'Bravo, you are our ally in fighting the terrorists which you (Assad) either created or brought in'," Attiyah told Reuters in the interview at Qatar's U.N. mission.
Although the Gulf Arab states all oppose Assad, Qatar has long faced criticism, for using its vast oil and gas wealth to back Islamic militants across the region, including groups in Syria.
Attiyah said those fighting Assad on the ground needed to be given more sophisticated means to tackle the government's "barrel bombing machine."
"They need to be given the means to defend themselves," he said. "Only then will Bashar understand he needs to come to the table, to have this political solution with him departing."
The United States admitted last week that U.S.-trained Syrian rebels had deserted and given weapons to al Qaeda-linked groups, and Attiyah questioned whether the strategy of training rebels to fight Islamic State rather than Assad was the best way forward.
"We have not treated the root of the cause. You cannot bring Syrian people and force them to go and fight Islamic State only," he said. "Their cause is not Islamic State, their cause is the regime. They will fight Islamic State, but they need to fight the regime first which created Islamic State."
He defended Qatar's efforts to aid Syrians fleeing the conflict in their country, responding to criticism that Gulf countries were not taking in any refugees since the conflict broke out four years ago.
He said Doha had spent some $1.6 billion in aid during that period and that since the conflict began the number of Syrians in Qatar had increased from 20,000 to 54,000.
Attiyah also said it was vital that Gulf Arab states and Iran develop a normal dialogue after Tehran had "overexaggerated" its criticism of Saudi Arabia after hundreds of people were killed during a haj pilgrimage there last week.
Shi'ite Muslim Iran is involved in a number of conflicts in Arab countries - including Iraq, Syria and Yemen - to strong opposition from the Sunni Arab states. The deaths in Mina in Saudi Arabia have heightened the acrimony between Saudi Arabia and Iran.
"We need to have a serious dialogue with the Iranians. We are neighbors and can't change the geography," Attiyah said. "We have to discuss all issues and leave nothing behind and only then we can have a normal relation between neighbors."