'Outrageous, ridiculous demands': US slams Iran as Tehran warns to 'rain down hell'

US secretary of state Marco Rubio on Sunday said diplomatic efforts to end the conflict with Iran have hardly made any progress, accusing Tehran of putting forward demands that Washington considers unrealistic.Speaking to reporters at Homestead Air Reserve Base in Florida before leaving for Paris to attend the G7 Foreign Ministers' meeting, Rubio said several countries were continuing to mediate between the two sides but cautioned against expectations of an imminent breakthrough, ANI reported, citing Al Jazeera."You have a number of countries that continue to engage them with different ideas, but I wouldn’t say we’re at the verge of a breakthrough," Rubio said.He said President Donald Trump remained open to resolving the conflict through diplomacy, but argued that negotiations could not advance under the conditions being proposed by Iran."If there’s a chance to do it, we’ll explore it.