Thousands of Schofield Barracks soldiers who have been hard at training for months for a pair of deployments to Afghanistan might not go, officials say.

Elements of the 3rd "Bronco" Brigade Combat Team, with more than 3,500 soldiers, and 4,300-soldier 2nd Stryker Brigade Combat Team were expected to deploy this summer as security force assistance brigades to train Afghan forces.

Before heading overseas, the two brigades were expecting to send several thousand soldiers each, along with equipment, to the National Training Center in California for final mission exercises with Afghan role players.

Those mission rehearsal exercises have been canceled, officials said Thursday.

The change in plans reflects the continuing drawdown of forces in Afghanistan, new budget constraints and a refocusing on the Pacific — all of which have created uncertainty as to exactly where the Schofield soldiers will go next.

The 25th Infantry Division is leaving it to the Pentagon to announce the Schofield soldiers’ next moves.

"The (Defense Department) will officially announce major deployments as they are approved," said spokesman Lt. Col. Derrick Cheng.

The training to prepare for Afghanistan will not go to waste, the brigade commanders maintain.

"With our recent refocus from Afghanistan to the Pacific area of responsibility, this training will be even more relevant and important," Col. Brian Eifler, who commands the 3rd Brigade, said in the January-February edition of the "Bronco Bulletin," the brigade’s newsletter. "In addition, we can look to return to theater engagements in the (region) like we have done in the past with Australia, New Zealand and Japan, just to name a few."

In the 2nd Brigade’s latest newsletter, Col. Thomas Mackey, brigade commander, and Command Sgt. Maj. Michael Crosby congratulated soldiers for the effort that went into the recent exercise "Warrior Spear" in preparation for the Afghanistan deployment. All nine infantry companies and three cavalry troops trained at Schofield with all their weapons systems.

"We got better every day that we executed Warrior Spear and we were ready to move forward and train at the National Training Center," Mackey and Crosby wrote. "The opening of our training schedule now offers us new opportunities to build upon what we have learned individually and as a team. We will take the opportunity to slow our pace and increase the quality of our training."

Adm. Samuel Locklear III, the head of U.S. Pacific Command and more than 328,000 U.S. troops in the region, told the House Armed Services Committee on Tuesday that one of the most visible signs of a "rebalance" to the Pacific can be seen in its ground forces, including soldiers and Marines, who are returning to duty in this theater.

"After a dozen years supporting wars in the Middle East, (Pacific Command’s) permanently assigned forces are resetting to focus on the Indo-Asia-Pacific," Locklear said, his first mention of the sea change.

Locklear said the Army recently removed the 25th Infantry Division at Schofield Barracks from worldwide service rotations, and elevated, at his request, the job of the U.S. Army Pacific commander from three to four stars.

Similarly, the Marines removed the III Marine Expeditionary Force — including Kaneohe Bay Marines — from worldwide duty, "allowing them to once again concentrate on Pacific theater missions," Locklear said.

The brigades were scheduled to deploy just a couple of months apart.

The 3rd Brigade previously said it was preparing for duty in volatile eastern Afghanistan, an area it was familiar with from a deployment to Kunar, Nuristan and Nangarhar provinces that ended about a year ago. Twenty soldiers were killed and 260 were wounded in action, according to the brigade.

On the now-doubtful deployments to Afghanistan, the soldiers were to have been parceled off into 12- to 20-member security force assistance teams to provide training to much larger groups of Afghans.