Russian Federation said in late June that it believed he had been killed in a bombing raid on Raqqa, but earlier this week Moscow admitted that it was unable to confirm the death and said it was getting contradictory information. "And I'll believe otherwise when we know we've killed him", Mr. Mattis said.
He said he also remains anxious by those who manage to escape home, bringing with them specialised skills like bomb-making, that they acquired in Syria and Iraq.
"Until I see his body, I am going to assume he is alive", Mattis said Friday.
In July, the Syrian Observatory for Human Rights (SOHR) said it had "confirmed information" that Baghdadi had been killed.
Talabany said Baghdadi was most likely hiding south of the eastern Syrian city of Raqqa, the de facto capital of ISIS's self-styled caliphate, which is under siege from a Kurdish-Arab force backed by the USA -led coalition.
NASA celebrates anniversary of Pluto mission with stunning flyover movie
The digital recordings were done by Paul Schenk and John Blackwell from Lunar and Planetary Institute, Houston. It released two videos, one of Pluto itself and a second of Pluto's largest moon, Charon.
"That was a very good lead. We just don't have information that would confirm his death".
There have been persistent rumors that al-Baghdadi has died in recent months, AFP reported. Unfortunately it was leaked in a prominent national newspaper about a week later and then he went dead.
Pentagon officials said Baghdadi was no longer is involved in the IS' day-to-day operations. Trump was seen miffed during the days of his Presidential Campaign when New York Times announced its support for rival and Democrat Hillary Clinton.
Moscow said that the strike came as senior Islamic State leaders were meeting to discuss their route out of al-Raqqa at the time of the Russian airstrike, which killed about 300 Islamic State fighters, including 30 commanders, Russia said. It's time that these leaks stop and the sources who frequent the Times and the Post are held fully accountable.