Nicaragua is in the midst of a deepening political crisis, with the opposition-controlled congress allegedly trying to topple elected President Enrique Bolanos. He has denounced what he say is a "slow-motion coup" in the country.
President Bolanos could also see his immunity removed
The BBC News website looks at what is behind the crisis and its possible consequences.
What is the origin of the crisis?
President Bolanos took office in 2002 after a landslide victory over Sandinista leader Daniel Ortega. But members of his own Liberal Party turned against him - and joined forces with former rivals the Sandinistas - angered by the government's decision to prosecute former President Arnoldo Aleman for corruption. Aleman is serving a 20-year sentence for fraud and money-laundering, but he still commands the loyalty of many of his party's legislators.
Why is congress being accused of trying to oust Bolanos?
Two of Mr Bolanos' ministers and three senior officials have been stripped of their immunity from prosecution so they can be investigated for alleged campaign funding irregularities.
Mr Bolanos himself faces having his immunity removed and possibly an impeachment. Congress is also debating constitutional reforms limiting the president's power, despite a ruling by the Central American Court of Justice which declared them inapplicable.
The president has said he will view any attempt to impeach him as a coup against his government.
Has Mr Bolanos received any support?
Nicaragua's Central American neighbours and the Organization of American States have expressed their concern over the crisis and backed the Nicaraguan president.
Visiting the country in October 2005, US Deputy Secretary of State Robert Zoellick demanded that Nicaraguan politicians halt their efforts to topple Mr Bolanos and reach an agreement with the government.
Why has the US stepped in?
Nicaragua is due to hold general elections next year. Observers say that Washington - which has expressed its unconditional backing to the Bolanos government - is concerned about the possibility of the Sandinistas returning to power. The Sandinistas were voted out of office in the 1990 presidential elections, after a 10-year civil war against the US-backed Contras.
If President Bolanos is ousted, what would the consequences for Nicaragua be?
Nicaragua could face isolation. The US has said that if Bolanos and his aides are impeached, this would immediately rule out a $175m US grant to Nicaragua and possibly $4bn of debt relief. The country could also lose its membership of Cafta, the Central American Free Trade Agreement which brings together the US and Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and the Dominican Republic.
There could also be consequences for Nicaragua's opposition leaders. Aleman's supporters could be barred from travelling to the US and other countries. This is a specially sensitive issue, because many Liberal Party members fled to the US or sent relatives there after the leftist Sandinista revolutionaries forced the Anastasio Somoza regime from power on 19 July 1979.