Akbar Hashemi Rafsanjani, also the head of Iran's powerful Expediency Council, is due to hold talks with officials including Sheikh Sabah al-Ahmad Al Sabah, the emir, and Sheikh Nasser Mohammad al-Ahmad Al Sabah, the prime minister.
Concluding a five-day visit to Syria, he said at a joint press conference with Farouk al-Sharaa, the Syrian vice-president, that an attack on Iran by the US was not in Washington's interests.
Rafsanjani said the UN Security Council had not endorsed any unanimous resolution for action against Iran over its nuclear activities. He accused the US of waging "a psychological war" against Tehran after it announced it had enriched uranium, the main plank of its nuclear programme.
"If the United States launched a military strike against Iran, that would be neither in its interests nor in the interests of the entire region," Rafsanjani said.
He said he believed that the US was "incapable of taking a risk or engaging into a new war in the region without discussing the subject seriously".
US media has reported that the Bush administration has been considering attacking Iran over its nuclear ambitions. Washington says Iran plans to produce nuclear weapons.
"If the United States launched a military strike against Iran, that would be neither in its interests nor in the interests of the entire region"
Akbar Hashemi Rafsanjani, former Iranian president
The talks in Kuwait will focus on the escalating crisis over the issue, officials and diplomats said.
Rafsanjani's visit follows Iran's announcement last week that it had enriched uranium to the level needed to make reactor fuel.
Sheikh Mohammad Al Sabah, Kuwait's foreign minister, said last week that Iran's nuclear activities must remain under the scrutiny of the UN nuclear watchdog, the International Atomic Energy Agency (IAEA).
"The countries in the region should be assured that Iranian nuclear activities were under the close watch of international monitoring, and that its safety precautions comply with international standards," he said.
Kuwait, a US ally, and other Gulf Arab states are concerned about the possibility that the current standoff may develop into a full-scale military confrontation and fear an environmental catastrophe from the Iranian nuclear plant being constructed in Bushehr.