"The Secretary-General welcomes the decision of the Supreme Court that paves the way for gay and lesbian Americans to have their relationships legally recognized, no matter what part of the country they live in," Ban's Deputy spokesperson Farhan Haq told reporters here.
Ban called the decision a "great step forward for human rights", reminding that his strong belief in equality and in the equal worth and dignity of lesbian, gay, bisexual and transgender (LGBT) people.
The Secretary-General joins the LGBT community and its millions of allies in celebrating this historic decision, he said.
In the historic decision, the apex court ruled by a five to four vote yesterday that the US that Constitution guarantees a right to same-sex marriage.
"No longer may this liberty be denied," Justice Anthony M. Kennedy wrote for the majority in the decision. "No union is more profound than marriage, for it embodies the highest ideals of love, fidelity, devotion, sacrifice and family. In forming a marital union, two people become something greater than once they were.