U.S. President Barack Obama sought on Monday to rebuild ties with Turkey, a Muslim country with growing clout whose help Washington needs to solve confrontations from Iran to Afghanistan.   Obama's two-day visit is a nod to Turkey's regional reach, economic power, diplomatic contacts and status as a secular democracy seeking European Union membership that has accommodated political Islam.   U.S. President Barack Obama has arrived in Turkey for the start of a two-day tour, the first predominantly Muslim country he is visiting since taking office. A visit closely watched in the Islamic world.   During his first day in Ankara, April 6, 2009 addressing the Turkish parliament, president Barack Obama called the country an important ally in many areas, including the fight against terrorism.   Then, on April 7, 2009 he attends a major international conference in Istanbul to promote East-West dialogue. So far, president Barack Obama has spent most of his first presidential trip abroad dealing with alliances. Those include the G20 for confronting the global economic downturn, NATO for reinforcing efforts in Afghanistan, and the EU for strengthening trans-Atlantic ties. Turkey is his only visit focused on a single state, and his only stop in a predominantly Muslim country before he heads home on April 8, 2009.