Adoption groups are warning a federal proposal that would give the State Department sole jurisdiction over international adoption could foster child trafficking, corruption, and delays for thousands of families awaiting children.

Supporters of the Intercountry Adoption Reform Act, or ICARE, say it would streamline the adoption process by transferring jurisdiction entirely to the Department of State from the Department of Homeland Security, which absorbed the Immigration and Naturalization Service’s role in adjudication and enforcement.

Some adoption groups are concerned that the bill would hamper protection against abuses of the system, and they fear that the legislation’s six-month transition period is too rapid for a system that handles about 20,000 adoptions a year.

“We fully support the policies and goals behind ICARE, specifically with respect to the immigration and promoting efficiency, however we are concerned the nuts and bolts are not in place,” said the executive director of Reaching out Thru International Adoption, Debbie Spivak.

A national organization advocating ethical adoption, Ethica, highlighted similar enforcement fears when they submitted a report to the senators’ offices this summer.

“ICARE effectively illustrates the lack of a national comprehensive policy on adoption,” the report states. But it goes on to say, with 17 of the 40 top countries of origin for adoptions from the past 15 years currently closed due to concerns about corruption, child trafficking, or abduction, they could not support the legislation until enforcement provisions were added.

An aide to Senator Landrieu, a Democrat from Louisiana and a co-sponsor of the bipartisan bill, said concerns over potential enforcement problems are being considered and said the proposed bill would ensure that adopted children are treated immediately as American citizens and would make the adoption system more efficient.

“One of the gaping holes in international adoption right now is it’s unregulated,” said the aide, who did not want her name published. “We don’t have a federal agency that has taking this as its responsibility.”

The bill’s backers said the new legislation would address this problem. “We’re pursuing every option to get this passed before we adjourn,” the aide from Ms. Landrieu’s office said. “We want to pass a bill that’s going to work.”