Argentina has deployed thousands of police in the Atlantic resort of Mar Del Plata, as the city prepares for the Summit of the Americas later this week.
Organizers say more than 30 heads of state from North, Central and South America are expected to attend, including President Bush. They will discuss issues affecting the hemisphere, including ways to create jobs and fight poverty.
In addition to deploying security officers, authorities have established a no-fly zone over Mar del Plata and limited access to the downtown area.
Meanwhile, protesters have begun to arrive in the resort for opposition activities expected to draw some 10,000 people.
Activists plan a citywide march on Friday, the first day of the Summit of the Americas, to protest the presence of President Bush. Many Argentineans criticize him for the U.S.-led war in Iraq, and for his support of a regional free trade agreement.
Some activists also say the economic policies he promotes do nothing to help Argentina's poor.
Some information for this report provided by AFP, AP and Reuters.