A letter of invitation or Affidavit of Support is not needed to apply for a visitor visa. Form I134 is used to document the personal finances of a sponsor who lives in the United States.Individuals immigrating through most family-based, and some employment-based,1 visa petitions are required to submit an Affidavit of Support on. The purpose of Affidavit of Support, Form I-134 is to affirm that a sponsor of a US Visa applicant can financially support the applicant while in the US. In order to fill out an affidavit of support as a sponsor, you must be a U.S. citizen or green card holder. An affidavit of support, (USCIS Form I-864), is required for all immediate relatives of US citizens and lawful permanent residents. A citizen of a foreign country who seeks to travel to the U.S. generally must first obtain a U.S. visa, which is placed in the traveler's passport. A Form I134 affidavit of support serves as a visa applicant's evidence of sponsorship, or evidence that the applicant has financial support. You must also submit an affidavit of support for your parent, referred to as the I-864 form. This form is required in most familybased green card applications, including CR1 and IR1 spouse visas and some employmentbased green card applications.