"People must be objective and fair while assessing what is happening in the (predominantly Tamil) northeast. There's 22% economic growth rate in the region, which is the direct result of a deliberate policy of investment," he told Hindustan Times on a visit to London.
"To try to put it in jeopardy is to destroy the lives of people there. How can you talk about lack of progress in the northeast? It's not like switching on a light bulb — you are dealing with the hearts and minds of people. There's a natural rhythm to everything."
Peiris said all but 3,000 of the Tamil refugees displaced by the 2009 war against Tamil militants had been resettled, and that the process would be completed within the month. "By any standard, that is a singular achievement."
Ties with India soured after New Delhi angered Colombo by voting for a US-sponsored UN resolution criticising Sri Lanka's human rights record in March. "It's a relationship of value to both countries and goes back such a long time. We have to move on - one incident cannot result in a rupture of relations.
"There are tensions from time to time, but that is to be expected. We all know of the situation in Tamil Nadu, whose politicians are trying to put pressure on New Delhi."
Describing fears of growing Chinese military influence as "a myth," he said: "We have made it clear that the soil of Sri Lanka will not be allowed to be used against another country."