KABUL, Afghanistan - Senator John McCain says the situation in Afghanistan will get more difficult before it gets easier, just like the surge in Iraq was.
The U.S. is preparing to pour thousands more troops into Afghanistan.
The former Republican presidential candidate is to report back to President-elect Barack Obama on what he saw on his trip to Iraq and Afghanistan.
McCain visited the southern province of Helmand, where he said NATO forces are at a stalemate with insurgents.
McCain said the U.S. will focus more on the Helmand region -- the heartland of the Taliban movement and a centre for opium poppy production.
The McCain trip comes at a time of increasing violence in Afghanistan, where a record 32,000 U.S. troops are now stationed, with requests for 20,000 more from American commanders.
There are also 2,500 Canadian troops stationed in southern Afghanistan.
In Afghanistan, insurgents this year have moved closer to Kabul, taking over wide swaths of countryside just south of the Afghan capital that are now unsafe.
Attacks on supply convoys on the road leading from Kabul to the southern city of Kandahar are commonplace.
In response, U.S. commanders are sending some 3,000 to 3,500 troops from the 10th Mountain Division to the provinces of Wardak and Logar for the first time next month, said Lt. Col. Rumi Nielson-Green, a spokeswoman for U.S. forces.
U.S. Brig. Gen. Mark Milley told The Associated Press last month that road security in the two provinces would be a priority.
"We want to get it so that any citizen can go from point A to point B on that road without fear," he said.
Milley said he expected to see an increase in violence south of Kabul over the coming months as the new troops attack insurgents.
The militants "will have a choice. Move somewhere else, reconcile, surrender, or die," he said.
McCain said it was clear there has been progress in the eastern part of Afghanistan, the region where most U.S. forces are stationed, but that Afghanistan's south deserves more attention.
"And I want to emphasize again, I think it's going to get harder before it gets easier, just like the surge in Iraq was," McCain said.
