The Department of Homeland Security has stated in writing that foreigners who are same-sex partners of American citizens can be included under an Obama administration policy suspending deportations of some immigrants who pose no security risk.

In letters sent late Wednesday to several Democratic lawmakers, Homeland Security Secretary Janet Napolitano said she was clarifying guidelines that enforcement officers had used when applying a policy of prosecutorial discretion in cases of illegal immigrants with no criminal convictions.

Under the guidelines, which were first issued in June 2011, officers can consider “ties and contributions to the community, including family relationships” when deciding whether to halt a deportation.

Ms. Napolitano wrote that she had ordered her department to issue written instructions specifying that those “family relationships” include “long-term same-sex partners.”