WASHINGTON (Reuters) - The United States is calling on all sides in Yemen to re-energize political talks to end the country s civil war, a Trump administration official said on Monday, after former President Ali Abdullah Saleh was killed in a roadside attack. Analysts said Saleh s death would be a huge morale boost for the Iran-aligned Houthis, since Saleh had switched sides by abandoning the Houthis in favor of a Saudi-led coalition. The U.S. official, who spoke on condition of anonymity, added that Houthi claims on Sunday they launched a missile at Abu Dhabi demonstrated  how destabilizing this war is for the region and how the Iranian regime is exploiting the war for its own political ambitions.  