"Export guarantees and investment guarantees from the Federal Ministry of Economics are still available to companies," the economy ministry said, Reuters reported.
The US will reimpose sanctions against Iran tonight.
Washington's sanctions are due to be reinstated against Tehran at 12:01 a.m. EDT on Tuesday, a US Treasury official said, speaking on condition anonymity.
Despite opposition from European allies, US President Donald Trump in May pulled the United States out of a 2015 deal between world powers and Tehran under which international sanctions were lifted in return for curbs on Iran's nuclear program.
Trump had denounced the deal reached under his White House predecessor, Barack Obama, as one-sided in Iran's favor.