LONDON — The United States will treat the visa applications of same-sex married couples in the same manner as opposite-sex spouses, Secretary of State John Kerry said Friday, announcing a policy change set in motion in June, after the Supreme Court struck down a law against same-sex marriage.

The policy change, which will take effect immediately, will apply to American citizens as well as foreign same-sex couples, dependent only on the marriage’s having taken place in a jurisdiction that recognizes same-sex marriage.

“Effective immediately, when same-sex spouses apply for a visa, the Department of State will consider that application in the same manner that it will consider the application of opposite-sex spouses,” Mr. Kerry announced at the American Embassy here.

“If you are the spouse of a U.S. citizen, your visa application will be treated equally,” he said. “If you are the spouse of a noncitizen, your visa application will be treated equally.”