The Americas were off limits to Europe as proposed in the Monroe Doctrine, not just one country.
Brazil
Your question did not specify any countries, but the Monroe Doctrine sought to put all of the Western Hemisphere off limits to European political or military activity.
The Monroe Doctrine was in direct opposition to the Truman Doctrine. The Monroe Doctrine said the US should not interfere with events in Europe.
France The French foreign minister said the Monroe Doctrine should "be resisted by all the powers having commercial or territorial interest in the hemisphere".
Monroe Doctrine stopped Europe from colonizing land from America.
The Monroe Doctrine told Europe to stop trying to create new colonies in the Western Hemisphere.
Europe: Yay, colonizing for personal gain! Monroe Doctrine: Not anymore! Stay out of South America!
limits European influence in the Western Hemisphere
The Monroe Doctrine
madison-monroe doctrine
The Monroe Doctrine opposed any future colonization of Latin America by Europe. It stated that that would be taken as a sign of aggression.