Helmand Province, Afghanistan (CNN) -- U.S. and Afghan commanders gave their troops pep talks Tuesday ahead of a planned assault on the Taliban stronghold of Marjah, a push touted as the largest of the 8-year-old war.
"I think some of our units will go into some very heavy contact and I think some of our units will have less contact. We don't know," U.S. Marine Brig. Gen. Larry Nicholson told American and Afghan forces at Firebase Fiddler's Green, in the southern province of Helmand. "All I know is that we have done everything we can to prepare, and on the eve of this operation, I think we're ready."
Operation Mushtarak -- "Together" in Afghanistan's Dari language -- is expected to be the largest NATO operation since the war began in 2001. The broadly telegraphed punch is aimed at the last major Taliban presence in Helmand, the scene of intense fighting between U.S. and NATO troops and the insurgents in the past two years.
The goal is to separate the Taliban fighters from the rest of Marjah's roughly 80,000 people, establish security and gain the trust of the remaining population -- the key objectives of the U.S. counterinsurgency strategy in Afghanistan.
"The population is looking for you, and the enemy is not the population," Nicholson told the Marines and Afghan troops. "But we do have an enemy that will try to hide in that population. That's why we've got to be very careful, and we've got to be very disciplined, and you've got to be very accurate."
The planned offensive is also said to have the largest Afghan National Army presence of any to date. Afghan Brig. Gen. Mohiyiden Ghori joined Nicholson on his tour of bases in the region Tuesday, telling Americans that U.S. engineers and contractors helped build much of the province's infrastructure in the mid-20th century.
"Your forefathers built Helmand. They built Marjah," he said, gesturing enthusiastically. "Americans built Marjah, and these terrorists destroyed the roads your forefathers built."
And Nicholson described the mission as "huntin' and helpin'."
"That's what we do." Nicholson said. "We either hunt them or help them. Sometimes we are doing both at the same time. And nobody's better at this than we are -- nobody."
As one Marine company prepared to move out, its members and the Afghan troops hugged and cracked jokes with each other. Ahead of the operation, the NATO command in Kabul put out a statement warning Afghan civilians to remain in their homes.
"Every effort is being made to ensure minimum disruption to the residents during the operation," it said.
Marjah is surrounded by fertile land where poppies grow easily, and the Afghan government's limited presence allows the drug trade to flourish. The production of opium helps finance the Taliban, the Islamic militia that controlled most of Afghanistan before the U.S. invasion in 2001.
Many of the Marines who will be taking part in Operation Mushtarak have fought in Helmand before. But the enemy is likely to fight harder this time, Lance Cpl. Christopher Lima said.
" They actually know how to fight this year," Lima said. "Last year they used a lot of guerilla tactics, shoot and then run. And this year, I think they'll try and stay around."
And the publicity given to the upcoming offensive has given the Taliban plenty to time to rig the potential battlefields with roadside bombs and other improvised explosive devices, the cause of more than 80 percent of U.S. and allied casualties in Afghanistan.
"The IEDs are getting more powerful, they're getting harder to detect. And they're just getting more forceful," said Lt. Cmdr. Gregg Gellman, a U.S. Navy doctor.
CNN Correspondent Atia Abawi contributed to this report.