Turkey is hoping that a meeting between President Tayyip Erdogan and his U.S. counterpart Joe Biden at next week"s NATO summit will yield positive results, Foreign Minister Mevlut Cavusoglu said on Wednesday, adding the meeting would be "critical". Biden and Erdogan will meet to discuss Syria, Afghanistan and other regional issues next week and will also discuss the "significant differences" between Washington and Ankara in their first face-to-face meeting since Biden took office, the U.S. national security adviser said on Monday. read more NATO allies Ankara and Washington have been at odds over a host of issues, from Turkey"s purchase of Russian S-400 missile defence systems - a move that drew U.S. sanctions last year - to regional policy differences, human rights, and legal matters. Speaking at an interview with state broadcaster TRT Haber, Cavusoglu said the allies needed to take mutual steps to repair ties, adding Washington was keen on working together with Ankara on regional conflicts such as Syria and Libya. "Our expectations need to be met too. As long as problems remain, it is not easy for us to sincerely build cooperation. We need to take mutual steps in every area," Cavusoglu said. "Our president"s meeting will be a critical meeting in every way. We hope the meeting will yield positive results," he added. The allies also have differing views on the Nagorno-Karabakh conflict and over Ankara"s oil and gas ambitions in the eastern Mediterranean. A statement by Biden in April calling the 1915 massacre of Armenians by the Ottoman Empire a genocide angered Ankara and stoked tensions. Despite these differences, officials say Turkey has offered to guard and run Kabul"s airport after NATO forces withdraw from Afghanistan, in a move that could serve as a potential area of cooperation between Ankara and Washington. read more Cavusoglu said on Wednesday that Turkey was discussing the security of the airport with allies, namely the United States, but that no country could handle that mission without support. U.S. Deputy Secretary of State Wendy Sherman, who held talks in Ankara last month, said Ankara and Washington had differing policies on some areas, but added that the allies needed to work on improving ties. "It"s not a simple relationship... but they are an important NATO ally for all of us," she told a virtual event organised by the German Marshall Fund. "I think we have to continue to work on building and sustaining that relationship, and encouraging Turkey to move in a direction where its democracy can really be real and strong and move forward."