The United States says Nicaragua's recent elections were "a setback to democracy" and warned it would now review aid to the country.
In a statement Wednesday, Secretary of State Hillary Clinton said the November 6 re-election of President Daniel Ortega was marred by significant irregularities.
The statement said the process was not transparent or impartial, and undermined the ability of Nicaraguans to hold their government accountable.
Clinton said the U.S. and other countries must therefore look for ways to hold Nicaragua accountable - such as applying "aggressive scrutiny" to project loans at the Inter-American Development Bank and World Bank. She said the U.S. will oppose any project that doesn't meet the "high standards" of the banks or provide adequate development impact.
The comments follow the final report of the Organization of American States election observation mission.
Ortega won more than 60 percent of the first-round vote in November, enough to avoid a runoff. A onetime Sandinista revolutionary, Ortega is the first Nicaraguan president to serve back-to-back terms since the end of the Somoza dictatorship in 1979.
He first came to power in 1984 after earlier leading a movement to overthrow the country's dictator Anastasio Somoza. He lost his re-election bid in 1990, but regained power in 2006.
Some information for this report was provided by AFP.