"We have formally communicated to the Government of Bangladesh that India would not be able to attend the forthcoming SAARC Summit in Dhaka on the scheduled dates" of February 6-7, Foreign Secretary Shyam Saran told a crowded press conference here.
A request has been made for fresh dates to be worked out through consultations among the member states, he said.
The decision was taken after Prime Minister Manmohan Singh, who was to attend the summit, discussed the developments in Nepal and the situation in Dhaka with his Cabinet colleagues, which was followed by a meeting of Cabinet Committee on Political Affairs and consultations with Opposition leaders Atal Bihari Vajpayee and L K Advani.
"This decision has been taken against the background of recent developments in our neighbourhood, which have caused us grave concern," Saran said.
He said the security situation in Dhaka has "deteriorated in recent days" following the fatal attack on former Finance Minister S A M S Kibria.
Soon after India's announcement, Pakistan, the current chairman of the seven-member grouping said that the summit has been "cancelled" and fresh dates would be worked out after consultations.
The summit, earlier slated to be held between January 9 and 11, was deferred due to tsunami disaster affecting three SAARC countries India, Sri Lanka and Maldives.
"There is no question of behaving like a big brother," the Foreign Secretary said while brushing aside the apprehensions about India being isolated in the seven-member regional grouping.
"There is no threat of isolation," he said when pointed out that all the other SAARC leaders, including Nepal King Gyanendra, had voiced no reservation in attending the Summit.
"It is only in an environment free from political turmoil and violence that a summit would yield the desired outcome," he said, emphasizing India's "continuing and consistent commitment" to the SAARC process and increased regional cooperation among member states.
External Affairs Minister K Natwar Singh called up Maldives President Abdul Gayoom, Bhutan King Jigme Singye Wangchuk and Sri Lankan Foreign Minister Lakshman Kadirgamar to convey India's decision and the reasons for it.
Saran said he had spoken to his counterparts in Bangladesh and Bhutan and New Delhi's decision was conveyed to Islamabad although he was not able to reach to Pakistan Foreign Secretary Riaz Khokhar.
Asked whether India's decision was influenced by the fact that Prime Minister Manmohan Singh would have to share the dais with Nepal King, who has seized power, Saran said "the decision has nothing to do with personalities."
India, he said, was looking for "amelioration and improvement" in situation so that some of its concerns were dispelled before deciding on the new dates.