The Prime Minister hit back at Pakistan over the incident at the Line of Control that resulted in the deaths of two soldiers and said there couldn't be "business as usual" until those guilty for the "barbaric act" were punished.
"After this barbaric act there cannot be business as usual with Pakistan," Singh told reporters while speaking on the sidelines of a function to mark Army Day.
"What happened at the LoC is unacceptable, those who are responsible should be brought to book," the Prime Minister told reporters.
He also expressed hope that Pakistan would realise that ties between the two countries would be affected if they failed to take action against those responsible for the killing of the two soldiers.
This is the first statement by the Prime Minister since the incident took place along the Line of Control that resulted in one soldier being decapitated, allegedly by Pakistani army regulars.
He has been regularly briefed by the National Security Advisor daily since the incident, which has sparked outrage in many parts of the nation.