President George Bush has arrived in Colombia for a meeting with President Alvaro Uribe on the latest stop in the US leader's tour of Latin America.
More than 100 protesters clashed with riot police near the presidential palace as Mr. Bush arrived in Bogota on Monday.
The president and Mr. Uribe are expected to discuss US support for Colombia's fight against drug trafficking and rebel groups. The Colombian leader's government has received four billion dollars in US aid in the past seven years.
Some Democratic Party lawmakers in the United States have raised questions about the level of aid, particularly because of a scandal linking some Uribe allies to paramilitary groups.
Mr. Bush is the first US president to visit the Colombian capital since Ronald Reagan in 1982 because of security concerns.
President Bush arrived in Colombia from Uruguay, where he emphasized the US friendship with Latin America (during talks with Uruguayan President Tabare Vazquez.
Mr. Bush has declined to respond directly to comments from Venezuelan President Hugo Chavez, who is making his own regional tour and has attended anti-Bush demonstrations.
President Bush said his administration is focused on what he called "quiet and effective diplomacy" in Latin America aimed at improving the "human condition."