MOSCOW (Reuters) - President Vladimir Putin signed a law on Friday that bans Americans from adopting Russian children and imposes other measures in retaliation for new U.S. legislation meant to punish Russian human rights abusers.

The law, which has ignited outrage among Russian liberals and child rights' advocates, enters into force on January 1 and is likely to strain U.S.-Russia relations.

As well as banning U.S. adoptions, it will also outlaw some non-governmental organizations that receive U.S. funding and impose a visa ban and asset freeze on Americans accused of violating the rights of Russians abroad.

Pro-Kremlin lawmakers initially drafted the bill to mirror the U.S. Magnitsky Act, which bars entry to Russians accused of involvement in the death in custody of anti-corruption lawyer Sergei Magnitsky and of other alleged rights abuses.

The restrictions on adoptions and non-profit groups were added to the legislation later, going beyond a tit-for-tat move and escalating a dispute with Washington at a time when ties are also strained by issues such as the Syrian crisis.

(Reporting By Alissa de Carbonnel; Editing By Steve Gutterman and Andrew Osborn)