Bogota, Mar 12: President George W Bush gave a vote of confidence to Colombia, promising to secure more aid and a trade deal for his close ally President Alvaro Uribe as he fights a rebel insurgency and drug traffickers.
The first US president to travel to Bogota in 25 years, Bush's seven-hour visit to the high-altitude capital was the midpoint of a five-nation Latin America tour shadowed by his leftist nemesis, Venezuelan President Hugo Chavez.
As Bush's armored limousine sped through the city, hundreds of protesters burned US flags, sprayed graffiti and smashed windows at banks and restaurants during clashes with police, who responded with barrage of tear gas and water cannon spray.
Bush's visit came as Colombia works to win approval of aid and a trade deal by Democrats in the US Congress, some of whom have expressed concern about human rights and a scandal tying some of Uribe's allies to paramilitary death squads.
Bush told reporters he would press for support of Uribe's efforts to bring to justice people linked to the right-wing paramilitaries, which are accused of atrocities and massacres in Colombia's four-decade-old conflict.
''It is going to very important for our United States Congress to see that determination and I believe that given a fair chance President Uribe can make the case,'' he said.
With Chavez's anti-US influence growing, Bush is seeking to improve ties with leaders of the right and moderate left in Latin America, where the Iraq war and US trade and immigration policy have made him deeply unpopular.
Washington's closest ally in South America, Colombia has received more than 4 billion dollar in mostly military and anti-narcotics funds since 2000, one of the largest US assistance packages outside the West Asia.
Uribe repeatedly defended his campaign, which has reduced violence by weakening Latin America's oldest rebel insurgency and disarmed illegal paramilitaries set up by landowners to counter the rebels.
But he is under fire after eight pro-Uribe lawmakers and his former security police chief were arrested on charges they colluded with the paramilitaries. Uribe says the probes show Colombian justice is working better than ever.
But some US Democrats want more guarantees before they approve the White House request for 3.9 billion dollars in new aid and a trade deal signed with Colombia. Critics say Uribe needs to do more to control the criminal influence of former militias.
The Bogota visit was meant to highlight security improvements, but the White House was not confident enough to let Bush stay overnight. More than 20,000 troops and police were deployed to keep him safe.
He traveled last night to visit conservative allies in Guatemala and later in Mexico.
Chavez, a former soldier who calls Bush the ''devil,'' was also traveling in a rival tour of the region during which the fiery populist has hurled insults at the US president.
Bush refused even to mention Chavez by name during stops in Brazil and Uruguay, where he courted free market-oriented leftist leaders he hopes will counterbalance Chavez and his quest for a regionwide socialist revolution.
''He doesn't dare to say my name. Several journalists have asked him this week 'what do you think of what President Chavez says?,' and he doesn't answer. His heart starts racing, he gets tongue-tied,'' Chavez said in El Alto, a poor city in Bolivia.
Colombia's violence has dropped sharply, but the rebels are still a potent force, mainly in rural areas. Colombia is still the world's largest cocaine producer, with the United States its biggest market.