David Cameron pledged today to "take no risks with British security" as his Government looks for ways to slash billions of pounds from the defence budget.
The Prime Minister said there would inevitably be "some big changes" a day ahead of a crucial meeting of his National Security Council which is expected to reach final agreements in some key areas.
Up to 10% savings are being sought from the Ministry of Defence and Mr Cameron told the Conservative Party conference the UK would "match our commitments with the resources we've got".
"This will mean some big changes. But I promise you this: I will take no risks with British security."
He also renewed his commitment to renewing Britain's nuclear deterrent system "based on" the Trident missile system and to withdrawing British combat troops from Afghanistan by the end of 2015.
Discovering the "catastrophic state" of defence spending under Labour was the biggest shock he faced after becoming Prime Minister, he told party members.
The UK would "not stay a day longer than we need to" in Afghanistan, he went on, paying tribute to those who have fought and died in the conflict.
"For those who have served, for those who bear the scars and for those who will never come home, this country has gratitude beyond words."Reuse content