The first minister warned that Wales could lose £400m in funding after EU leaders agreed a budget limit for the next seven years.
The EU budget cut makes the poorest areas of west Wales and valleys vulnerable, the first minister Carwyn Jones said.
Prime Minister David Cameron said it would be good for the UK and Europe.
Carwyn Jones responded with disappointment. “The Prime Minister says this is a ‘good deal for Britain’. He will need to explain how it’s a good deal for Wales.”
“We are disappointed that the agreement fails to deliver the level of investment in jobs and growth needed in Wales,” he added.
The budget will be 3% lower than the current seven-year period, amounting to 908bn euros (£787bn) from 2014 to 2020.
The spending for cohesion and common agricultural policy would be reduced from €354.5bn to €325bn and €336.4 to €278, respectively. By contrast, competitiveness and rural development and fisheries would face an increase.
Carwyn Jones also referred to countries like Spain and Italy.
“Some regions, like those in Spain and Italy, have secured special payments to compensate for such cuts”, he said, “but the UK Government failed to negotiate similar protection on our behalf.”
But Professor James Foreman-Peck from Cardiff University said: “I don’t think there will be any change in Welsh markets.”
“I don’t think the EU finance spending has long lasting beneficial effects on the Welsh economic,” he added.
All figures based on 2011 Euro prices, Figures may not sum due to rounding.
207-2013 budget for 25 countries, 2014-20 budget for 28 countries. Off-budget spending in 2007-2013 totalled €40bn. Off-budget spending in 2014-2020 is €37bn.
Open Europe and European Council