Peabody Public Schools expects a roughly $100,000 increase in diesel costs this school year, putting added pressure on a budget already stretched by rising expenses for transportation and other essentials. The district operates 26 school buses and pays a fuel surcharge under its transportation contract when diesel prices rise above $3.75 per gallon. If prices remain at current levels, the extra bill could be equivalent to the cost of employing a teacher with benefits, said Sam Rippin, the district’s chief financial officer. Officials may freeze nonessential spending if they cannot cover the increase through savings elsewhere. That could limit discretionary classroom purchases and teacher professional development, Rippin said. The district is also considering consolidating bus routes to reduce transportation costs. “You have to pay the utility bill. You have to pay the transportation bill,” Rippin said. The pressure is not unique to Peabody. Glenn Koocher, executive director of the Massachusetts Association of School Committees, said districts across the state are likely to face higher expenses for transportation, heating oil, food deliveries and other services. Adjusting budgets partway through the fiscal year can be especially difficult, he said, and districts may have to use reserves or cut back on supplies. The increase comes amid disruption in global energy markets linked in part to the war in Iran. President Donald Trump has announced an agreement with Russia intended to bring more diesel to the United States, but the amount of relief it could provide and when prices might fall remain uncertain. Rippin expects to bring possible budget solutions to the Peabody School Committee within the next month. Any route changes or spending restrictions would come as district leaders work to manage higher operating costs without reducing resources available to students and staff.