WASHINGTON (AP) -- The nation's top military leader says U.S. approval of a long-spurned high seas treaty would strengthen American naval power.

In prepared testimony Wednesday, Army Gen. Martin Dempsey told Congress that the U.N. Convention on the Law of the Sea would ensure navigational rights and freedoms needed to project and sustain U.S. military forces.

In a rare step underscoring Obama administration support for the treaty, Dempsey was testifying along with Defense Secretary Leon Panetta and Secretary of State Hillary Rodham Clinton.

The treaty was concluded in 1982 and has been in force since 1994. The U.S. is the only major nation that has refused to sign the treaty, which has been endorsed by 161 countries and the European Union.

Members of the tea party fear the treaty will undermine U.S. sovereignty.