The first Deputy Secretary of defense Patrick Shanahan from January 1, 2019 will be the acting head of the Pentagon after the resignation of James Mattis. This reported in his Twitter the President of the country Donald Trump.

“I am pleased to announce that the talented first Deputy defense Minister Patrick Shanahan will become the acting head of the Pentagon from January 1, 2019. Patrick has a great track record, he has achieved a lot during his work as a Deputy Minister, and before that — in the Boeing company,” the US President wrote.
About changing the head of the Pentagon Trump reported earlier in his Twitter. “General Jim Mattis resigns, having served as defense Minister for two years,” – said the American President.

The head of state thanked Mattis for his contribution to the development of new weapons and fulfillment of allied obligations towards other countries.