"This has been a bloody October for UN peacekeeping," Ban said.
"In Darfur, Mali and the Central African Republic, we have lost 14 peacekeepers in hostile acts -- nearly one per day."
The two peacekeepers were serving in the joint United Nations-African Union mission deployed in late 2007 to help end bloodshed between militias, rebel forces and gangs in Darfur.
A wave of attacks in northern Mali have left 31 peacekeepers dead since July last year, while a Pakistani blue helmet serving in the Central African Republic was killed last week in an ambush.
"Blue helmets must be allowed to undertake their life-saving work without interference," Ban told reporters at UN headquarters in New York.
The UN's 130,000 troops, police and civilian staff serving in missions worldwide are being drawn into more complex conflicts while being tasked with enforcing fragile peace deals.