Extra money will be available to fight "troubling" security threats to Northern Ireland the Prime Minister, David Cameron, promised on Thursday.
A third of the PSNI's budget goes on combating terrorism. There has been a series of recent bomb attacks by dissident republicans.
The Real IRA said it planted a device in Londonderry last month.
Mr Cameron said the government was "standing by the commitments" made by former Prime Minister Gordon Brown.
"We believe we are meeting those, but his is something we have to keep under review," Mr Cameron said.
"There was agreed access to the (money) reserve as proposed by the former prime minister, and we stick to that."
Policing and justice powers were devolved from Westminster to the Northern Ireland Assembly earlier this year.
The Tory leader added: "Having devolved policing and justice it is very important that we say to colleagues in Northern Ireland that you must try to make the best you can with that.
"We should not try and stand on their shoulders the whole time."
Mr Cameron said the Government was honouring commitments by the former prime minister on funding the creation of a policing college near Cookstown, County Tyrone.
He also added security issues in Northern Ireland had been discussed by the National Security Council.
"The security situation is troubling," he said.
There have been several attacks in recent months blamed on dissident republicans.
In August, a car containing 200lb of explosives went off outside Strand Road police station in the city, causing substantial damage.
Two men hijacked a taxi in the Bogside, loaded the bomb into the driver's car and ordered him at gunpoint to leave it at the station.
Home Secretary Theresa May is among those warning of the heightened risk.