Tehran, May 10 -- Iran questioned the seriousness of American diplomacy on Saturday in the wake of renewed naval clashes in the Gulf, while keeping Washington waiting for a response to its latest negotiating position. US President Donald Trump had said on Friday that he was expecting Iran's response to Washington's latest proposal on a deal to extend a fragile truce and launch peace talks -- "supposedly tonight". But, if Iran did send the talks' Pakistani mediators a response, there was no public sign of this, and Tehran's Foreign Minister Abbas Araghchi called into question the reliability of the US leadership, in a call with his Turkish counterpart. P16...