During his speech, Streeting said the government has “agreed more than £11.8bn worth of contracts” in the 10 days since the publication of the Dip.
Streeting added: “But investment is only one side of the coin because while we will always back our brave men and women who serve, ensuring they have the resources and the kit that they need, we also owe it to them and to the whole country to ensure that every penny is spent wisely.
“Modernisation without investment is impractical, but investment without modernisation is irresponsible.”
Streeting said he embarked on a “bold programme of reform and modernisation” during his time as health secretary to ensure “that we were maximising value for money and cutting waste”.
He said this reduced waiting times for hospital treatment in England and led to millions more appointments.
Streeting added: “This is the mantra I will now follow as defence secretary.
“This is how we make ourselves fit to face the future, how we will continue to be a strong, dependable ally to our friends abroad, and how we will be an engine of growth and jobs here at home.”
In February, Streeting responded to the hospital waiting list in England dropping to its lowest level in nearly three years by saying there had been good progress but there was “much more to do”.
The Ministry of Defence was recently criticised over its “unbelievable” waste and inefficiency by Labour MP Al Carns, who also quit as a defence minister during the row over funding for the Dip.
Carns told The Guardian, external last month: “You turn a stone over and get another shock – how has that been allowed to go on?
“And you turn another stone over, and it is just layers of bureaucracy which now cost us more than the product you’re getting itself.”
