By Sophie Kiderlin LONDON, July 8 (Reuters) - The pound held steady on Wednesday as U.S. President Donald Trump said that an interim agreement to end the war with Iran was "over" after Tehran carried out new attacks on U.S. bases in the Gulf. Brent crude futures jumped after Trump's comments, made before a NATO summit in Turkey, and were last up 5.61% to $78.36 a barrel. The reaction in currency markets was relatively muted, with the U.S. dollar index last little changed on the day.