USCIS.gov now has an online dictionary (glossary). You can use this dictionary to quickly look up a definition or explanation for a topic.Each financial sponsor (petitioner, any joint sponsors, and any household members) must submit an Affidavit of Support as well as evidence of their finances. A sponsor must be at least 18 years old and either an American citizen or a lawful permanent resident. (LPR). An affidavit is a written statement made under oath or affirmation. It's used as evidence in legal proceedings. My Petitioner is unemployed, does he or she need to fill out an Affidavit of Support? Form I-134 is a promise to financially support a person applying for a temporary visa to the United States, namely a travel visa or a K-1 fiancé visa. An affidavit is a document in which a person gives facts, and swears that the facts are true and accurate. The signer is required to demonstrate proficiency in the language in which the document is written.