US Defense Secretary Donald H. Rumsfeld, on an unannounced holiday season visit, hinted on Thursday that the US military soon will begin a modest, additional reduction in troop levels by canceling the scheduled deployment of two Army brigades. The decision would be the first Pentagon move to drop the American troop presence below the 138,000 level that had been considered a baseline prior to the temporary addition of about 20,000 troops to provide extra security during the October 15 referendum and the Dec. 15 election. Rumsfeld had previously said those 20,000 would be leaving soon. But in an interview with reporters traveling with him on an Air Force cargo plane to Baghdad, Rumsfeld hinted that a preliminary decision had been made to go below the 138,000 baseline by not deploying a brigade of the 1st Infantry Division from Fort Riley, Kansas, and a 1st Armored Division brigade now in Kuwait. Other officials have said small parts of each brigade were likely to go anyway. The decision comes as the administration of US President George W. Bush is under pressure by critics to begin withdrawing troops from Iraq. Bush, however, has rejected talk of a withdrawal timetable, saying this would only embolden the insurgency, leave the US prone to new attacks and undercut the goal of securing a stable future for the new Iraq. Asked whether he'd made the decision to hold back those two brigades, Rumsfeld made a distinction between his decisions as defense secretary and final announcements by the US government. "Until it's announced, the government's decision hasn't been announced. Therefore it's not final," he said. Two weeks ago, two defense officials told The Associated Press that the Pentagon tentatively planned to cancel the scheduled deployment to Iraq of the 1st Infantry Division's 1st Brigade and instead send small teams from that unit to Iraq to train security forces. They also said the 1st Armored Division's 2nd Brigade would not go to Iraq, as planned. Instead, up to two-thirds of that brigade would return to Germany, where they are usually based, and the rest would remain in Kuwait. The officials spoke on condition of anonymity because the plans were not final. Rumsfeld also said he hoped that the Iraqis who will be putting together a full-term national government in coming weeks will take into account the risk of losing international support if they stumble. "It's a big, big, enormous thing for them to try to accomplish in a relatively short period of time," he said, referring to the job of selecting a president, a prime minister and cabinet ministries. "We also can't ignore the fact that the world - the rest of the world - has a vote," he said, referring figuratively to other countries' choices about the extent of their future support for Iraq. "The degree of support will be, to some extent, a function of the critically important decisions they (the Iraqis) make during this period." Rumsfeld said he hopes the government leaders who emerge are "people who are going to pull that country together toward the center and not pull it apart - people who are competent and capable of leading a government, a wartime government." It was the second such surprise visit in less than a week. Vice President Dick Cheney appeared here last Sunday. Earlier, Rumsfeld said that while the administration is planning troop reductions in Afghanistan, removing forces too quickly would impede the long-term hunt for terrorists. "If we were to withdraw from Afghanistan precipitously, or from Iraq, the terrorists would attack us first somewhere else and then they would attack us at home, let there be no doubt," Rumsfeld said at Bagram Air Base. In a holiday season pep talk, Rumsfeld spoke to several hundred soldiers in a heated tent at Bagram that serves as the main airfield for US forces in Afghanistan. "The momentous changes here could not have happened without your service," he said. On Wednesday, Rumsfeld reassured the Afghan government that planned cuts in the number of US troops will not weaken the US campaign to capture and kill Taliban fighters and al-Qaida terrorists.