ISTANBUL — Vice President Joe Biden on Friday will become the latest in a parade of US officials trying to push Turkey to step up its role in the international coalition's fight against the self-proclaimed Islamic State extremists. His visit comes after weeks of public bickering between the two NATO allies. The Turkish president insists that if the US wants his help, it must focus less on fighting IS and more on toppling Syrian President Bashar Assad. Erdogan wants the US-led coalition to set up a security zone in northern Syria to give moderate fighters a place to recoup and launch attacks. The US has no appetite to go to war against Assad and has said a no-fly zone against Syria's air force is a no-go. Turkey has pledged to train and equip moderate Syrian forces on its soil, but no details have been announced by either side. — AP
