United States officials have strongly criticized the measure and have urged the Russian government not to enmesh orphaned children in politics.
"It is misguided to link the fate of children to unrelated political considerations," a State Department spokesman, Patrick Ventrell, said on Wednesday before Mr. Putin announced his decision.
Internally, however, Obama administration officials have been engaged in a debate over how strongly to respond to the adoption ban, and are trying to assess the potential implications for other aspects of the relationship between Russia and the United States. The United States, for example, now relies heavily on overland routes through Russia to ship supplies to military units in Afghanistan, and has enlisted Russia's help in containing Iran's nuclear program. The former cold war rivals also have sharp disagreements, notably over the civil war in Syria.
Until Thursday, these larger considerations, along with the possibility that Mr. Putin might veto the adoption bill, seemed to forestall a more forceful response from Washington.
The ban is set to take effect on Tuesday, and some senior officials in Moscow said they expected it to have the immediate effect of blocking the departure of 46 children whose adoptions by American parents were nearly completed. Adoption agency officials in the United States who work regularly with Russian orphanages said they expected the number of families immediately affected by the ban to be far larger, about 200 to 250 who have already identified a child that they plan to adopt.