India has contributed nearly 180,000 troops over the years, the largest number from any country.
"I salute the professionalism, dedication and courage of men and women who have served in UN peacekeeping operations. I also pay solemn tribute to those who have laid down their lives for the cause of peace.
"In particular, I extend my heartfelt condolences to the families of the 126 peacekeepers, including 2 peacekeepers from India, who made the supreme sacrifice in 2014," Swaraj said in a message on the occasion of UN International Day of Peacekeepers which will be celebrated tomorrow.
"I also take this opportunity to recall the cardinal principles of peacekeeping which sustain it as a mechanism to maintain international peace and security, viz. Consent of the parties, impartiality and non-use of force except in self-defence and defence of the mandate.
"These principles continue to be as relevant as ever today and central to the respect and regard that the Blue Helmets have earned for themselves," she said.