"He (Zardari) is the democratically elected President and as per law, he enjoys immunity as long as he holds office," Ashraf told reporters last night.
He said all legal experts had given the government the same opinion on this issue.
On Wednesday, the Supreme Court gave Ashraf time till July 12 to indicate whether he would ask Swiss authorities to reopen graft cases against Zardari.
Ashraf's predecessor Yousuf Raza Gilani was convicted of contempt and disqualified by the apex court after he refused to act on orders to revive the corruption cases against Zardari.
Both Gilani and Ashraf have contended that the President enjoys immunity from prosecution within Pakistan and abroad.
The Supreme Court has been pressuring the government to revive the cases against the President since December 2009, when it annulled a graft amnesty issued by former military ruler Pervez Musharraf that had benefited Zardari and over 8,000 others.
Asked specifically whether he would write to Swiss authorities to reopen the cases against Zardari, Ashraf said he would announce his decision on July 12.
Immunity is enjoyed not only by the Pakistani President but all Presidents of the world, he said.
The question of Presidential immunity has been blown out of proportion though there is no ambiguity on the issue, Ashraf said.
"If there is no right decision, it can create chaos in the country. Therefore, we should avoid such decisions and take appropriate decisions that do not damage the country," he said.
In this regard, he said that when the judiciary was attacked in the past, all political parties and the people came out to defend it.
If something similar happens to Parliament, people will come out to save it, he added.
Ashraf said the uncertainty prevailing in Pakistan is harmful to institutions and undue importance given to a single issue might be detrimental to democracy.
"Institutions should work within their Constitutional ambit and let people decide about the future of the democratically elected government since it is they who matter," he said.
He urged all stakeholders to respect the Constitution and work within Constitutional parameters to avert any kind of instability.
The government will take all possible steps to ensure a transparent, free and fair general election, he said.
Replying to a question, Ashraf said the Pakistan army has been playing a vital role in the defence of the country.
Appreciating the courage and commitment of the army, he said: "We are proud on our armed forces as they are a source of strength and national stability."