Erdogan wants to buy American drone aircraft to attack separatist Kurdish fighters belonging to the Kurdistan Workers' Party (PKK), which has bases in the mountains in northern Iraq, near the Turkish border.
"The president has said to Erdogan that some of the actions that Turkey has taken have caused questions to be raised on the Hill [Congress]," an unnamed administration official said in the Financial Times report.

Loss of confidence

The United States voiced disappointment after Turkey voted against fresh UN sanctions on Iran, which the United Nations Security Council adopted in June.

Ankara argued that Tehran should be given a chance to carry out a nuclear fuel swap deal, which was brokered by Turkey and Brazil.

Relations between Turkey and Israel were thrown into disarray after Israeli commandos on May 31 raided a Gaza-bound flotilla of six ships loaded with aid trying to run the blockade of Gaza in an operation in which nine Turkish activists were killed.

The bloodshed triggered international criticism of Israel and dealt a heavy blow to Turkish-Israeli ties.

Obama called on Turkey to cool its rhetoric about the raid when he met Erdogan at the G20 summit in Toronto in June, the FT report said.

Al-Qaeda tirade

Ayman al-Zawahiri, al-Qaeda's second-in-command, has criticised Turkey's "ties" with Israel and its role in Afghanistan, urging it to restore the traditional role of the former Ottoman Empire, in an audio message posted online.

Obama called on Turkey to cool its rhetoric about Israeli raid on Gaza-bound flotilla [AFP]

"Change will come when the Turkish people ask their government to stop co-operating with Israel and recognising it and to stop sending their forces to kill Muslims in Afghanistan," a man identified on Sunday as Zawahiri by US monitoring group SITE said in the 20-minute audio tape.

The authenticity of the statement in which Zawahiri began by offering condolences to the families of those who were killed as well as to the Turkish people could not immediately be verified.

Al-Qaeda's number two, who has a US bounty of $25m on his head, made similar comments against the Turkish government in an Internet message in late July.

At the time he also urged Turkey to assume the traditional leading role of the Ottoman Empire as the defender of Islam.