Carter, who reportedly plans to meet exiled Hamas leader Khaled Meshaal in Syria, said he viewed Hamas's inclusion in peace talks as "very important" and stressed he was not travelling as an official US negotiator.
"It's very important that at least someone meet with the Hamas leaders to express their views, to ascertain what flexibility they have, to try to induce them to stop all attacks against innocent civilians in Israel and to cooperate with the Fatah as a group that unites the Palestinians," Carter told ABC news.
"There's no doubt in anyone's mind that, if Israel is ever going to find peace with justice concerning the relationship with their next-door neighbours, the Palestinians, that Hamas will have to be included in the process," he said in the interview, which was pre-recorded and aired on Sunday.
Carter arrived in Israel Sunday as part of a "study mission" that runs until April 21, his Atlanta-based Carter Center said. The trip will take him to Israel, the occupied West Bank, Egypt, Syria, Saudi Arabia and Jordan.
Media reports that Carter plans to hold talks with Meshaal in Damascus sparked furore in the United States. Carter's office would neither confirm nor deny the reports, and the former president has remained vague about the details.
"I've not confirmed our itinerary yet for the Syrian visit, but it's likely that I will be meeting with the Hamas leaders," Carter said in the interview.
Israel on Sunday urged Carter not to meet Meshaal.
"Such a meeting would be all the more shameful as Jimmy Carter symbolises peace," senior Israeli defence ministry official Amos Gilad told military radio.
He was referring to Carter's role as the architect of the 1979 Egypt-Israeli peace treaty and the fact that he won the Nobel Peace Prize in 2002.
"Meeting with Hamas leaders would show support for this movement without the minimal conditions set by the international community for such a dialogue, namely a recognition of Israel's right to exist and the accords reached in the past with the Palestinians," Gilad said.
"Hamas' strategic goal of destroying the state of Israel has not changed," the reservist general added.
The Islamist Hamas, which seized control of the Gaza Strip last June after routing Fatah forces loyal to Palestinian president Mahmud Abbas, is considered a terrorist organisation by Israel, the United States and the European Union.
However, the 83-year-old Carter pointed out during the ABC interview that he was not travelling in any official capacity.
"I'm not going as a mediator or a negotiator," he said. "I've been meeting with Hamas leaders for years."
Carter said his most recent talks came after the group's win in January 2006 elections. At that time, he said Hamas expressed willingness to declare a ceasefire in Gaza and the West Bank and allow Abbas to negotiate on behalf of all Palestinians.
"I intend to find out if these are their prevailing thoughts now," he said.
On Sunday in Jerusalem, Carter is scheduled to meet Israeli President Shimon Peres and the parents of Gilad Shalit, an Israeli soldier seized in a June 2006 cross-border raid from the Gaza Strip and who is being held by Hamas.
Israeli Prime Minister Ehud Olmert appeared to shun Carter, as the two were not scheduled to meet during his four-day visit to Israel and the Palestinian territories.
"Carter is going to visit places we do not wish to associate ourselves with. He also never made an official request to meet Olmert," a senior government official told AFP.
The US State Department on Thursday advised him against meeting Hamas because Washington supports Abbas in new peace talks with Israel and backs the Jewish state's bid to isolate the Islamists.
Carter's 2006 book "Palestine: Peace, Not Apartheid" infuriated Jewish groups who accused him of racism and anti-Semitism.
© 2008 Agence France Presse