Responding to the issue raised by the Opposition in both Houses of Parliament, Singh noted that the country is agitated over Italy's action which is "unacceptable" and said the government will pursue diplomatic channels to bring the two marines back.
Urging the Italian authorities to respect the undertaking given to the Supreme Court, he said they should return the two accused - Massimiliano Latorre and Salvatore Girone - to stand trial here for the incident of February last year.
The Prime Minister, who made a similar statement in Rajya Sabha, said the government has already made it clear that this action by the Italian government is "not acceptable".
"If they do not keep their word there will be consequences for our relations with Italy," Singh said firmly, adding that bilateral relationship has to function on the basis of trust.
More From This Section
Assuring Parliament that the government would continue to urge Italy through diplomatic channels to send back the marines, he wanted the members to act and speak together while dealing with the matter with the seriousness that it deserves.
Rajya Sabha also witnessed uproar over it with demands for arrest of the Italian ambassador Daniele Mancini.