He said they could either hand over the money from their budget or accept a cut in the Barnett formula funding they receive from their Westminster block grants.
The request was highly unusual, as foreign aid and defense spending is reserved for Westminster.
However, SNP ministers in Edinburgh have previously voluntarily spent money on other reserved areas, such as international development, by sending aid to other countries, including Ukraine.
They have provided £4 million to provide basic humanitarian aid in the areas of health, water and sanitation, and shelter for those fleeing the war-torn country.
The Scottish government said its £65 million would be used to fund “advanced air defense systems and thousands of essential equipment for Ukrainian soldiers”.
‘Financing of these areas must be donated by the British government’
Ms Forbes said: “This further funding is intended to help the Ukrainian armed forces fight against Russian aggression and the unspeakable brutality being committed.
“We have agreed to provide funding on this occasion, given the clear need to maximize the international effort to support Ukraine. However, it is clear to us that this should not be seen as a precedent leading to returned budgets being used to fund clearly reserved policy areas.”
Ms Evans said it was “correct that the UK should continue to provide much-needed military support and we will continue to provide humanitarian assistance to the many people from Ukraine who arrive in Wales every day”.
But she added: “What is not right is using money that should be for investment in returned areas, such as health care and education, to fund an unreturned spending area – military aid and defense.
“We have accepted this result because of our continued commitment to support the Ukrainian people and to avoid future fiscal uncertainty, but funding for these areas should rightly be funded by the British government.”
Jeremy Miles, the Education Minister for Wales, told BBC Radio Wales the ministers had been “told by the UK Treasury that the budget would be cut” and that “there had been no consultation”.
David TC Davies, a minister for Wales, said: “Ultimately the Parliamentary government will do nothing to undermine devolution.”