WASHINGTON, (Reuters) – President Barack Obama  presented a unified front with Afghan President Hamid Karzai yesterday in a bid to show their differences were behind them  and the United States was on track to start withdrawing troops  next year.

The Obama administration, backing away from a publicly  tough approach to Karzai widely believed to have backfired,  gave the Afghan leader the red-carpet treatment in the  culmination of a four-day visit at a pivotal time in the  nine-year-old war.

The White House talks were meant not only to reassure the  Afghan leader of a long-term U.S. commitment to his government,  but to convince a skeptical American public and Congress that  the war is worth fighting and funding.

Standing side by side with Karzai, Obama played down  strains in relations in recent months marked by Washington’s  open criticism of Karzai for tolerating corruption and the  Afghan leader’s angry rebukes against his Western allies.

“I am confident we are going to be able to achieve our  mission. There are going to be setbacks, there are going to be  times when the Afghan government and the U.S. government  disagree tactically, but I think our overarching approach is  unified,” Obama told reporters.

While U.S. concerns about corruption have not faded and  questions remain whether Karzai can be a reliable partner, the  Obama administration is making a concerted effort to handle  such matters in private and treat the Afghan president with  more respect in public.

Injecting a cautionary note, Obama warned of “hard  fighting” in coming months as U.S.-led forces prepare to mount  an offensive in the Taliban stronghold of Kandahar. The push  awaits completion of a 30,000-troop buildup Obama has ordered.

But he also said he was confident he will be able to meet  his promise to begin withdrawing U.S. forces in July 2011 as  more security duties are turned over to Afghan forces.