WASHINGTON (AP) — The war in Afghanistan will get worse before it gets better, President Barack Obama warned on Wednesday, but he declared his plan to begin withdrawing U.S. forces next year remains on track.

Standing alongside Afghan President Hamid Karzai, Obama said, “What I’ve tried to emphasize is the fact that there is going to be some hard fighting over the next several months.” The two leaders spoke at a White House news conference as U.S.-led forces in Afghanistan prepare to push hard into the Taliban’s birthplace in Kandahar Province in June. The campaign for Kandahar, already under way in districts outside the city, is expected to be among the bloodiest of the nearly nine-year-old war.

“There is no denying the progress,” Obama said. “Nor, however, can we deny the very serious challenges still facing Afghanistan.”

Karzai’s warm White House welcome followed months of sniping and frustration over management of the war and about fraud allegations surrounding Karzai’s re-election last year. Both leaders said disagreements are normal with so much at stake.

“There are moments when we speak frankly to each other, and that frankness will only contribute to the strength of the relationship,” Karzai said with a smile.