Washington/Tehran, April 10 -- Ahead of the US-Iran talks in Islamabad, the tone on both sides remained increasingly sharp on Friday, as Tehran and Washington warned of resuming military action should no deal be reached.

While US has insisted on a deal that will put 'America First', Iran has demanded the fulfilment of all its terms and warned of a 'crushing response' over failure to do so.

From Washington, White House Deputy Press Secretary Anna Kelly said: "President Trump has a proven track record of achieving good deals. and he will only accept one that puts America first," adding he remains "optimistic that a deal can be reached that can lead to lasting peace in the Middle East."President Donald Trump, striking a highly aggressive ton...