However, a Secret Service spokesman said the fuel did not pose any danger, and crews are in the process of cleaning it up.
Spokesman Max Milien said Monday the truck was leaving the White House grounds when it sprang a leak. A hazardous materials team from the District of Columbia arrived soon after and ensured the scene was safe.
Workers poured sand and gravel on the fuel to soak it up, then used brooms to collect the residue.
The spill took place ahead of a late-morning speech by President Barack Obama at the U.S. Chamber of Commerce, across the avenue - and Lafayette Park - from the White House.