Oil has already fallen for three straight weeks as diplomatic efforts surrounding Syria and Iran eased concerns about Middle East supplies.

Lavrov said Russia would press for an international conference to make Middle East a zone free of weapons of mass destruction.

Vietnam is prone to floods and storms which kill hundreds of people and cause millions of dollars in damage each year.

"I thoroughly understand his state of mind, but I cannot justify or share the strategy," said Health Minister Beatrice Lorenzin.

Kerry said the sanctions could be lifted after an agreement was in place that ensured Iran's nuclear program was peaceful.