LONDON, Oct 7 (Reuters) - A leading Syrian Kurdish politician said on Thursday the United States will stay on in Syria to destroy Islamic State, build infrastructure and remain a player in the search for a political settlement after more than 10 years of civil war. The Kurds, who live in the mountainous region straddling the borders of Syria, Armenia, Iraq, Iran and Turkey, carved out self-rule across northeast Syria during the civil war that began in 2011. President Bashar al-Assad was supported by Russia and Iran while the Syrian Kurdish YPG militia was backed by the United States. But in 2019 then-President Donald Trump pulledmost U.S. forces out of Syria to enable a Turkish offensive against the Kurds. The chaotic Western withdrawal from Afghanistan stoked concern across the Middle East that Trump"s successor Joe Biden might abandon allies across the region as Washington perceived China to be the main strategic challenge.But Ilham Ahmed - president of the executive committee of the Syrian Democratic Council, the political arm of the YPG - said the United States had given a clear commitment to the Kurds. "They promised to do whatever it takes to destroy Islamic State and work to build infrastructure in North Eastern Syria," he told Reuters after meetings in Washington with White House, State Department and Pentagon representatives."They said they are going to stay in Syria and will not withdraw - they will keep fighting Islamic State," Ahmed said. "Before they were unclear under Trump and during the Afghan withdrawal, but this time they made everything clear." Syria"s minority Kurds, who were discriminated against by Assad"s pan-Arabist ruling Baath party, run a civilian administration that governs the affairs of several million Syrians once ruled from Damascus.The Kurds have asked the Americans to help re-open the Al-Yaarubiyah border crossing between Syria and Iraq for international aid, and to play a role in helping a political settlement, Ahmed said. Ahmed, who met Russian Foreign Minister Sergei Lavrov in Moscow last month, said the Kurds had also been speaking to the Russians - "the main player in Syria"- and was ready for dialogue with Iran too. The Kurds have spoken to Damascus in an attempt to find a political settlement. How optimistic is Ahmed?"We don"t see much happening in the short term... We are hoping the Americans will play a more active role for a Syrian political settlement - they should do."