On the People’s Republic Of China’s new Air Defense Identification Zone (which the PRC demands that all aircraft intending to fly through it check in with the Chinese government first), an airspace grab that goes with its grab of the East China Sea below, the Obama administration has had this response.

National security spokesman Patrick Ventrell:

pointed to White House press secretary Jay Carney’s remark that “the US government does not accept or recognize China’s newly declared” defense zone.

State Department spokesman Marie Harf:

[W]e’ve been very clear that we’ve called on China not to implement the ADIZ, and we’ll continue to do so.

JCS Chairman Martin Dempsey:

So it wasn’t the declaration of the ADIZ that actually was destabilizing.  It was their assertion that they would cause all aircraft entering the ADIZ to report regardless of whether they were intending to enter into the sovereign airspace of China. And that is destabilizing.

Vice President Joe Biden:

the US is “deeply concerned.”

And

crisis management mechanisms and effective channels of communication between China and Japan to reduce the risk of escalation.

President Barack Obama:

Not even that much.

PRC President Xi Jinping:

…took on board what the Vice President laid out….

Yeah.  We showed ’em.