Loss of U.S. Nationality
If you would like to renounce or relinquish your U.S. citizenship, find more information on the Montevideo U.S. Citizens Services Navigator. Renouncing U.S. citizenship is a two-step process and may require more than one visit to the U.S. Embassy. During the first step, you will receive information on renouncing/relinquishing your U.S. citizenship. You will later be given the required paperwork to fill out. On your second visit to the Embassy, your paperwork will be reviewed and you will speak to a U.S. Consular Officer to finalize the renunciation/relinquishment process.
There will be a a US $2,350 fee to document formal renunciation of U.S. citizenship.
More information relating to the loss of citizenship is on this Travel.State.Gov information sheet.