President Donald Trump is leaning toward maintaining sanctions against Russia that were adopted by the Obama administration in response to Moscow’s alleged interference in the U.S. presidential election, a senior administration official said Thursday.

Mr. Trump has said he will keep sanctions on Russia imposed by the U.S. and its allies following Moscow’s intervention in Ukraine in 2014. But the president has left open the possibility of lifting Russia sanctions that were enacted by the U.S. in December by former President...