With tensions running high between the US and Russia over the latter's military intervention in Ukraine's Crimea peninsula, US Secretary of Defense Chuck Hagel has advised his Russian counterparts to be cautious.
"Let's keep the tensions down, let's see no provocative actions by anyone. This is a time for very cool, wise leadership," Hagel said.
The Pentagon has plans to induct more than 2,400 F-35 fighter jets into the military, but has earmarked funds for only 35 of the controversial planes in next year's budget. "Almost every hardware programme the Pentagon buys costs twice as much and takes twice as long to deliver - and it gives you about half the performance you thought you were going to get in the beginning," said Gordon Adams, a defence budget analyst at the Stimson Center.