Philip Hammond is expected to confirm 1,400 job losses in the Army but the Head of the Army said there will be no more "forced exodus".
The Defence Secretary has defended the use of unmanned aircrafts as the UK's drone nerve centre was revealed for the first time.
The Ministry of Defence has confirmed how much it has spent on the failed attempt to part-privatise its defence procurement arm.
The former head of the Army, Lord Dannatt, has told ITV News he believes female soldiers should not be allowed to serve in front line roles.
Gen Dannatt, who led the Army from 2006 to 2009, said combat situations in which units attack with "violence, bayonets and machine guns" are "not the right place" for women to be.
Defence Secretary Philip Hammond has said the armed forces must review the role female soldiers can play in combat situations to ensure women know the organisation is "fully open" to them.
Mr Hammond said the reality of the armed forces is "very different" from the "macho image" that he said many continue to apply to it.
But he said the restrictions on women in combat situations is "something we have to look at again", in part because of the "message" it sends to women "who might be looking to join other parts of the military".
It is a move that the head of the army, General Sir Peter Wall, has already suggested might make the armed forces "look more normal" - and it seems Defence Secretary Philip Hammond now agrees.
He has ordered a review of whether women should be allowed into combat to start immediately, and wants a report on his desk by the end of the year.
Earlier he told journalists that if the US, Australia and even France had women in combat roles, it was time for Britain to look at the policy again.
Currently, there are more than 16,000 women in the armed forces but about 30 per cent of roles are closed to them.
The Defence Secretary says he does not envisage the numbers who apply will be that large but suggests it is time to send a signal that the army is open "to all who can meet the standards required".
It is also true that if the change does go ahead next year, it will not harm the Government's attempts to appeal to women voters in the run up to the General Election.
The Malaysian transport minister's communications team has posted an image of him talking on the phone - in his dressing gown - to Defence Secretary Philip Hammond about the Royal Navy submarine arriving to help search for the missing Malaysia Airlines flight:
Defence Secretary Philip Hammond said Russia has been using a "crude and very blunt instrument" by amassing troops on the Ukraine border.
Mr Hammond told the BBC's Andrew Marr Show: "We're concerned that there might be a further incursion in the territory of a sovereign nation.
"But whether there is or there isn't, we all ought to be concerned about the use of this crude and very blunt instrument to try to influence other nations and their behaviour".
The Defence Secretary has dismissed much of the criticism levelled against the Government on Army cuts as "nonsense".
Speaking on the BBC's Andrew Marr Show, Philip Hammond said: "We still have the fourth largest defence budget in the world.
"I was in the Pentagon just this week past, I heard my US counterpart talk about Britain as a credible, capable and reliable ally and that's what we intend to remain.
"Of course we've had to make savings, of course we've had to make some very tough decisions, ... but we're looking to the future not the past."
Defence Secretary Philip Hammond confirmed the Government will offer Typhoon aircraft to Nato from late April to assist with the Nato-Baltic air policing mission.
Mr Hammond told MPs, "I hope that will provide reassurance to our Nato allies" following the Crimea referendum result and the ongoing Ukraine crisis.
Independence poses a threat to both levels of safety and security and the future of defence jobs in Scotland, Defence Secretary Philip Hammond has told the Conservative Party conference.
Addressing the party's Scottish conference in Edinburgh, with just over six months to go until the referendum, Mr Hammond said the Scottish Government's defence plans under independence are not credible.
"A separate Scotland could not hope to develop the same level of protection and resilience," Mr Hammond said.
"Whether it's the range of military capabilities; the strength of our geopolitical influence; or the number of domestic defence jobs we are able to sustain, it is absolutely clear that replicating the UK's level of safety and security [...] under a separate Scotland is probably impossible."
Defence Secretary Philip Hammond has accused a committee of MPs of failing to recognise the need to counter evolving threats, such as potential cyber-attacks, meant there had to be a shift in the balance of defence spending.
Mr Hammond said:
It is not possible to maintain traditional regular forces at historic levels while also investing in countering the threats of tomorrow.
The Army 2020 structure is not simply about a reduction in size; it is a complete overhaul of how the Army works to deliver a fully-integrated force, using a better mix of regulars, reserves and contractors to get the maximum defence effect from the budget.
The military could have been brought in earlier to help deal with the winter storms that have been wracking Britain, a Cabinet minister has admitted.
Defence Secretary Philip Hammond defended the Government's handling of the crisis.
He said Royal Engineers were now being tasked to carry out a high-speed assessment of "serious" damage to the UK's flood defence infrastructure.
But Mr Hammond conceded that in future the Government would involve the military earlier in the process, and be more "aggressive" in urging local authorities to use troops.
Mr Hammond said more than 3,000 troops were currently deployed to help and 5,000 more were available if needed.