Prime Minister Theresa May will reveal details of a jobs and education package to help the most vulnerable victims of the Syrian conflict.
The £1bn package, which includes £840m that was promised last year and £160m of new money, aims to give support to refugees and the countries hosting them.
It will be unveiled by the PM during her visit to Jordan, where she will visit a school that is educating refugees alongside Jordanian children.
Jordan has more than 650,000 registered Syrian refugees.
The announcement also comes ahead of a Syria conference in Brussels on 4 and 5 April.
The package aims to give refugees incentives to remain close to Syria rather than making the journey through Europe and potentially to the UK.
It includes food, vaccinations, shelter and basic care for refugees in Syria and across the region; education for children in Jordan and Lebanon over the next three years and funding for infrastructure.
It will also seek to create thousands of new jobs, vital building work, help for small and medium-sized businesses in Lebanon and technical advice to Jordanian and Lebanese governments to increase the growth of jobs and the private sector.
The Government has been criticised for its approach to the humanitarian crisis, especially when a scheme to help unaccompanied child refugees was scrapped after taking around 350 youngsters rather than the 3,000 that campaigners hoped for.
But Mrs May insisted the UK was a "kind and generous country".
"Hundreds of thousands of people have lost their lives and millions more have been forced to flee their homes by the barbarity of the Syria conflict," she said.
"The UK has led the international response to the defining humanitarian crisis of our generation, and will continue to set the pace.
"The ambitious approach agreed in London last year is delivering real results and giving refugees what they want - opportunities and education close to home that provide a meaningful alternative to risking their lives trying to reach Europe. This is clearly in the UK's national interest.
"We are a kind and generous country that will never turn our backs on those who so desperately need our support."
The Government said total UK funding for dealing with those affected by the Syria conflict stands at £2.46bn.
Earlier on Monday, Mrs May was flown by helicopter to a military base on the outskirts of Amman, where she inspected military weapons such as rocket-propelled grenades, snipers and drones; and met troops.
Mrs May held talks with King Abdullah over increasing defence and security ties between the UK and Jordan, which she said played an important role in maintaining stability in the region.