While US mediators, alongside diplomatic backchannels, prevented a bigger conflagration, President Trump's offer has put Delhi in a spot. "Obviously, it would not be welcome by the Indian side. It goes against our stated position for many years," Shyam Saran, a former Indian foreign secretary, tells the BBC.

A series of military strikes last week by India and Pakistan brought the nuclear-armed rivals closer to a broader war.

Iran's foreign minister warned Britain, France and Germany on Monday that a decision to trigger a U.N. mechanism reimposing sanctions on Tehran could lead to an irreversible escalation of tensions.