Raja said this at the inauguration of a three-day national conference of 'All India Peace and Solidarity Organisation' on the theme 'Struggle for a better India and a better world'.
"All issues should be sorted out through dialogue and negotiations and no other mode could bear a lasting solution," he said.
At the same conference, CPI(M) leader Sitaram Yechury said there should be greater expenditure on food and elimination of poverty.
He said AIPSO was an effective forum to ensure that foreign policy was implemented without deviating from its spirit and goals.
Inaugurating the conference here, Puducherry Chief Minister N Rangasamy said the Union Territory was ideal venue for the forum since the region is known for communal and religious harmony.
"...Stalwarts like Sri Aurobindo and thinkers like Subramanya Bharathi and Bharathidasan had enriched Puducherry by their contributions," he added.
More than 300 delegates from across the country are participating in the three-day conference.