A former top advisor to U.S. President Barack Obama said on Tuesday that there is still time to stop Iran’s nuclear program using economic and political pressure.

Dennis Ross, Obama’s former Middle East advisor, said that the Obama administration is committed to preventing Iran from obtaining nuclear arms as a “vital national security interest,” according to a report by The Washington Post.

Ross, who stepped down last month, said Iran is behind schedule on its nuclear program and battered by some of the worst strain seen in the country in three decades. He added, however, that more pressure is needed to prevent its leaders from acquiring a nuclear capability that would destabilize the region and heighten the risk of war.

“Ratcheting up the pressure continues to be the answer,” The Washington Post quoted him as having said. But, he added, “We’re not quite there yet.”

Ross made the comments during a gathering at the Washington Institute for Near East Policy. It was his first public address since leaving the White House.

“This is not about containment; it’s about prevention,” The Washington Post quoted Ross as having said. “I believe we still have time and space to achieve that objective.”

Ross also addressed the peace process between Israel and the Palestinian Authority and downplayed chances for a breakthrough on peace in the near future.

He cited a “huge gap, psychologically,” between Israeli and PA leaders and conceded there was “not a high prospect” of achieving a comprehensive peace settlement soon. He added that it would be a mistake for Israeli leaders to wait until the current Middle East tumult subsides before pursuing peace.

“There are many in Israel who look at the region and say, ‘Now is not the time,’” Ross was quoted as having said. “If you sit back and wait for things to clarify, you will be acted upon. Your options shrink; they don’t expand.”

He acknowledged that there were difficulties in the Obama administration’s relations with the government of Prime Minister Binyamin Netanyahu in the past three years but said that ties between the two countries were “solid.” He said both shared the same assessment of the threat posed by Iran.

Ross announced last month he would resign from his White House post, saying he had made a promise to his wife to return to private life after two years in the administration and had outstayed that promise by a year.

He added that he was returning to private life with “mixed feelings.”

Ross, along with the U.S. Mideast peace envoy David Hale, visited Israel in September hoping to avert the Palestinian Authority’s unilateral statehood bid at the United Nations. They were unsuccessful and PA Chairman Mahmoud Abbas submitted his statehood bid to the Security Council on September 23.