UK Prime Minister David Cameron will be promising an additional £12 billion for strengthening defence forces in the lower house of Parliament on Monday, as part of the five-year Strategic Defence and Security Review (SDSR).

The SDSR and National Security Strategy (NSS) together encompass the threats to the UK and the nation's military capabilities in dealing with them.

The SDSR will have a list of changes and additions, such as two "strike brigades" of 5,000 people by 2025 that will be able to respond to "diverse threats" immediately, a fleet of maritime patrol aircraft and an extension to the lifespan of the RAF's Typhoon jets, giving them ground-attack capabilities.

In a foreword to the review, the UK PM wrote: "At its heart is an understanding that we cannot choose between conventional defences against state-based threats and the need to counter threats that do not recognise national borders," about the strategy. "Today we face both and we must respond to both."

He added: "So over the course of this parliament our priorities are to deter state-based threats, tackle terrorism, remain a world leader in cyber security and ensure we have the capability to respond rapidly to crises as they emerge."

Britain has also committed 2% of its gross domestic product on defence to meet a NATO target, reports AFP.

The additional funding will set the spending on defence by the UK at £178 billion over the next decade, reports

Cameron is also expected to argue for airstrikes in Syria to fight Isis. France, the US and Russia are already conducting airstrikes in the country.