The US fears Turkey will launch a new offensive in northern Syria that Washington has warned against, a senior American diplomat said on Wednesday. "We are deeply concerned by recent increased rhetoric from Turkey about potential military moves into the north of Syria," Assistant Secretary of State for Near Eastern Affairs Barbara Leaf told a congressional hearing. "We've stepped up our diplomatic engagements to attempt to stop that," she said. Asked if Ankara would give up such plans in light of US efforts, Ms Leaf replied: "I couldn't give you the assurance that they are going to." Turkey has numerous times since late May threatened to conduct a new military operation in northern Syria to target Kurdish fighters. Among them are the People's Protection Units (YPG), which were supported by the US-led international coalition against ISIS. Washington <a href="https://www.thenationalnews.com/world/us-news/2022/06/01/blinken-warns-turkey-against-launching-offensive-against-kurdish-forces-in-syria/" target="_blank">has repeatedly advised against such an offensive</a>, which it believes could destabilise the region and jeopardise the struggle against terrorism. The issue highlights the continuing tension between Nato members Washington and Ankara, at a time when Turkey <a href="https://www.thenationalnews.com/world/us-news/2022/05/18/us-confident-of-nato-accession-for-sweden-and-finland/" target="_blank">opposes Finland and Sweden's bids to join</a> the Atlantic alliance.