Striking a defiant tone, Mr Obama said leaks to news media could endanger the lives of military and intelligence personnel.

BBC: Obama tries to tame political tempests

Is there any concern that this is -- this defiant tone will complicate or pose an obstacle to the talks?

WHITEHOUSE: Press Briefing

Iran's parliament echoed the defiant tone by saying it would consider an immediate halt of oil exports to Europe to pre-empt the oil embargo, which the EU set to begin on July 1 to give its members time to find alternative supply sources.

WSJ: Iran Blasts West Over Oil Embargo

At the same time, he pushed back against Democrats who would like to see Obama react by adopting a more defiant Democratic tone.

WSJ: Obama raises cash for Dems in New York

And despite a conciliatory tone at times, he was ultimately resolute and even defiant.

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