Singh, who quit the Congress in 2008 after being associated with the party for over two decades, said it is for the first time in his former party's over 130 years of history that it is without a president.
His criticism of the grand old party came while speaking on Indo-Pak ties at the launch of a book 'Indo-Pak relations -- Beyond Pulwama and Balakot' by U V Singh.
Natwar Singh, who was the External Affairs Minister in the early tenure of the UPA-I government, said the huge majority for Modi has established that he is a leader to be reckoned with.
"If there is anybody who can make a move with regard to Pakistan it is him. I don't see him doing so in the near future," he said.
Recalling his meeting with Modi before he became prime minister, Singh said he had told the then Gujarat chief minister that he should invite neighbours when he is sworn-in as PM.
"He (Modi) did that not because I said so, but I guess it stuck in his mind," the former diplomat said.
Singh claimed that if the Balakot airstrikes and the Pulwama attack had not happened, Modi would have got 250 seats instead of 303.
"So, I think that Mr Modi has been elected for two terms until something drastic happens because my former party, the Congress party, is, to put it mildly, in very poor shape. I don't see any drastic change in the revival and re-invention of the Congress party in the near future," the 88-year-old leader said.
"The working committee has not met for the last seven weeks. The Congress party for the first time in 134 years does not have a president. So in this political situation, Mr Modi is in a very strong position both nationally and internationally," he asserted.
Rahul Gandhi, during the crucial meeting of the Congress Working Committee on May 25, had quit as party chief. He had made it clear that the grand old party should find a new president other than anyone from the Gandhi family.
Talking of Indo-Pak relations, Singh said they are accident prone and it was unlikely that they would get better in the near future.
He also asserted that there was no solution for the Kashmir issue.
Singh said that the problem in the ties is also generated as Pakistan is obsessed with India and suffers from "chronic inferiority complex".
He also slammed Pakistan for not recognising that the International Court of Justice verdict in the Kulbhushan Jadhav case was in favour of India.
Singh said Pakistan Prime Minister Imran Khan had made sensible statements on India but it remains to be seen how far the military will allow him to go in bettering ties with India.