US President Barack Obama on Tuesday nominated Marine General Joseph Dunford as the next chairman of the US Joint Chiefs of Staff.Praising Dunford as one of American military's "most highly regarded strategic thinkers", Obama emphasised General Dunford's role in ending the US combat operations in Afghanistan."Under his steady hand, we've achieved key milestones, including the transition to Afghan responsibility for security, historic Afghan elections, and the drawdown of US forces," Obama said.Dunford began his career as an infantry officer. As a widely-respected commander in the US who led the Afghanistan war coalition during 2013-2014, he will succeed Army General Martin Dempsey, who is retiring this year as the top military advisor to Obama and Defense Secretary Ashton Carter.Dunford is expected to be easily confirmed by the Senate, as Senator John McCain, chairman of Senate Armed Services Committee, said shortly after Obama's personnel announcement on Tuesday that his committee would give the nomination "prompt and thorough consideration"."In addition to his leadership of the Marine Corps, Gen. Dunford's exemplary service in Iraq and Afghanistan makes him a strong choice as we confront threats to stability and peace in both countries and throughout the region," Xinhua news agency quoted McCain as saying in a statement.If confirmed, General Dunford would be the second Marine officer to hold the top military job.Dunford, 59, is a native of Boston, the capital of the US state of Massachusetts, and holds master's degrees in government from Georgetown University and international relations from Tufts University's Fletcher School of Law and Diplomacy.