Ties between Iraq and Turkey have deteriorated since Iraqi Prime Minister Nouri al-Maliki issued an arrest warrant for Hashemi. Hashemi took refuge in Kurdish-run northern Iraq before leaving the country for Turkey following the charges. He's the subject of an Interpol Red Notice.
Hashemi faces charges he orchestrated a death squad in Iraq. He told the BBC he was ready to return to face the charges but expressed concern about his security.
"I am ready any time," he said.
He added that he wanted the United Nations to get involved in the situation, adding those who've given evidence against him have done so during harsh interrogation techniques that he said amounted to torture.
The BBC cited allegations that Hashemi, now in Istanbul, ordered the assassination of a Sunni leader for "going off message."
The U.N. Security Council in a report last month said that, while the security situation in Iraq had improved in general, security challenges exist in large part because of political intransigence.