The bishops said that discrimination against homosexuals is unjust. But they insisted they had an obligation to "give witness to the whole moral truth'' and reinforce Catholic teaching that homosexual sex is a sin, the Associated Press reported.
Vermont allows civil unions between homosexuals, and laws in California and Hawaii extend some economic benefits to same-sex couples.
The bishops approved the statement by a vote of 234-3, with three abstentions. The prelates decided to end their meeting Wednesday night, one day early.
The bishops also overwhelmingly approved a statement raising concerns about the ethical dimensions of agriculture and trade policy. The statement "'For I was hungry and you gave me food': Catholic Reflections on Food, Farmers and Farmworkers" also contains a suggested "Catholic Agenda for Action."
The statement highlights the pressing need for U.S. Catholics to "connect their faith to the ethical and human dimensions of food and agriculture issues," according to Bishop Ronald Gilmore of Dodge City, Kansas, chairman of the bishops' Ad Hoc Committee on Agricultural Issues.
According to the statement, the world is "facing new challenges: increasing concentration at every level of agriculture, increasing focus on agricultural trade as a measure of economic vitality, and increasing globalization tying together our lives and livelihoods wherever we live. ... These forces of increasing concentration and growing globalization are pushing some ahead and leaving others behind."
On one of the more challenging issues related to agriculture, the bishops seek a middle course. "We recognize that agricultural subsidies can have a damaging effect on struggling farmers in developing nations," explained Bishop Gilmore.
"We're not suggesting that we should wipe the slate clean, but we believe we can reduce and target U.S. subsidies so that small and moderate sized farms can compete while the negative impacts on developing countries are minimized," he said.
"For too many in our Church and nation, agriculture is a distant reality, little seen and less understood," said Bishop Gilmore. "The document examines agricultural issues in the light of Catholic social teaching, encouraging Catholics to seek the 'common good' on issues of food and agriculture and affirming the dignity and rights of farmers, ranchers and farmworkers, both here and around the world."
The document, which builds on previous bishops' statements, is the work of the bishops' Ad Hoc Committee on Agricultural Issues. Over the past four years the committee conducted listening sessions with farmers, ranchers, academics, policy-makers, farmworkers, growers, representatives of rural organizations and corporations, and government officials.