Iran isn't likely to start or provoke a conflict with its neighbours or the U.S., an intelligence official told a U.S. Senate armed services committee hearing Thursday.

"Iran can close the Strait of Hormuz, at least temporarily, and may launch missiles against United States forces and our allies in the region if it is attacked," said Defence Intelligence Agency director Lt.-Gen. Ronald Burgess.

The country — under pressure from western economic sanctions — might also try to use terrorist surrogates around the world to destabilize its enemies.

Despite all that, however, "the agency assesses Iran is unlikely to initiate or intentionally provoke a conflict," Burgess testified.

Earlier this week, three Iranians were detained in Bangkok after accidentally setting off explosives. On Thursday, Thailand's top policeman confirmed that the group was plotting attacks there against Israeli diplomats.

The allegation came after two days of accusations by Israel that Iran was behind the botched plot — as well as two others in India and the former Soviet republic of Georgia this week. Iran has denied the charges.

Director of National Intelligence James Clapper said it's "technically feasible" that Tehran could produce a nuclear weapon in one or two years, if its leaders decided to build one, "but practically not likely."

He says recent diplomatic outreach by Iran to European diplomats could indicate that officials there are reconsidering the program.

Both men said they do not believe Israel has decided to strike Iran.

With files from The Associated Press