"If any Iraqi leader wants to enter Iran legally, we will naturally reject it. But if they come illegally, we will try them for the crimes they have committed against our people," the television quoted Foreign Ministry spokesman Hamid Reza Asefi as saying. 

"Iranian guards carefully watch any activities on our long western border with Iraq," Asefi said. 

The lengthy war between the two countries killed or wounded nearly 1 million people. Iran holds the Iraqi president responsible for the deaths of soldiers and civilians when Iraq used poison gas against Iranian troops. 

Despite Iran's opposition to Saddam - no peace treaty was ever signed after the United Nations brokered a ceasefire - it strongly opposed the U.S.-led military campaign against Iraq. Iranian relations with the United States were severed after the 1979 Islamic revolution, when militants stormed the U.S. Embassy in Tehran and took hostages. 

Asefi said he was assured on Sunday by British Foreign Office minister Mike O'Brien that the presence of U.S.-led forces in Iraq will be "limited." He said Iran will continue to seek war reparations from Iraq. Iran claims it sustained an estimated $1 trillion damages from the war. 

Meanwhile, British Foreign Secretary Jack Straw rejected fears Monday that Iran was on the target list after Iraq. 

"We've been developing better diplomatic relations with Iran," he told the British Broadcasting Corp. radio from Bahrain. "We're grateful to the Iranians for the support and cooperation which they gave during the course of this military conflict."