Pressed on the issue, he said: "We don't need to reveal everything beforehand."
DMK president M Karunanidhi on Sunday said his party, which has five members in the council of ministers, would pull out of the United Progressive Alliance (UPA) if the government did not take steps to bring amendments to the US-sponsored resolution against Sri Lanka in the UNHRC.
Karunanidhi told reporters in Chennai: "If our requests are not heeded, our relationship with the United Progressive Alliance (UPA) will not continue."
He said he has written to Prime Minister Manmohan Singh and UPA chairperson Sonia Gandhi on Saturday to bring amendments to the resolution holding the Sri Lankan government responsible for genocide.
He also called for a probe into the allegations of war crimes and the crime of genocide against the Tamil people.
Sri Lanka is under attack over the death of a large number of Tamil civilians during the final stages of the war that crushed the Liberation Tigers of Tamil Eelam (LTTE) in 2009.
The DMK has 18 MPs in the Lok Sabha.