Coming out strongly against the menace of terrorism, President Pranab Mukherjee on Thursday said mutual cooperation between two nations cannot be promoted under the shadow of cross-border terrorism. Adding that no state should be allowed to sponsor or harbour the perpetrators of the cowardly acts of terror, the President called on the international community to work together to thwart and isolate those who indulge in cross-border terrorism. President Mukherjee was addressing a gathering at the India and Nepal- Exploring new vistas’ in Kathmandu.