In the early 1800s, Great Britain offered to help the US stop other European nations from establishing colonies in the Americas by making a joint statement opposing colonization. The joint statement expressed their opposition to any further colonization efforts by European powers in the Western Hemisphere. This statement became known as the Monroe Doctrine, named after US President James Monroe, who announced it in 1823. The Monroe Doctrine asserted that the Americas should no longer be considered open to colonization and that any attempt by European nations to establish new colonies or interfere with the newly independent countries in the Americas would be viewed as a hostile act. Great Britain's support and endorsement of the Monroe Doctrine helped to solidify its significance and influence in international relations and served as a deterrent to further European colonial expansion in the Americas.