Defense Secretary Donald H. Rumsfeld (search) and his Argentine counterpart on Tuesday discussed the expansion of scientific cooperation and joint military exercises, with the Pentagon chief praising stronger ties between the two nations.

Rumsfeld and Defense Minister Jose Pampuro also focused on Argentina's role in U.N. peacekeeping operations in Haiti (search), where 550 troops are participating in the 10-month-old international mission.

Pampuro told reporters in a brief statement that the operation is a "remarkable example of regional responsibility." After landing in March 2004 to halt violence, the U.S. military turned over the mission in Haiti to allies, but the peacekeepers have been criticized for inaction in the face of widespread violence.

Following the meeting, Rumsfeld said he and Pampuro discussed ways to expand scientific and technological cooperation. They also discussed further joint military exercises.

"The relationship between the United States and Argentina continues to strengthen," Rumsfeld said, adding that "the people of Argentina can take pride in their important global role."

After touring a cathedral in the Argentine capital, Rumsfeld was to visit Brasilia, Brazil and Guatemala.

En route to Argentina on Monday, Rumsfeld said the international forces in Haiti have done a generally good job. Brazil leads the mission with more than 1,100 troops. Argentina is second-in-command in the operation. Guatemala also has sent soldiers.

Rumsfeld has promoted the Haiti effort as an opportunity for nations in the Americas to work together. But officials fear that foreign commitments of aid are not being fulfilled, leaving reconstruction lagging as fall elections approach.

The Bush administration has encouraged Argentina to increase security in the "triple frontier" region along its borders with Brazil and Paraguay. Rough jungle terrain and lax controls in the area have raised fears of criminal and terrorist elements operating at will.

About 629,000 people live in the region stretching across the borders, and authorities say that population includes 23,000 people of Lebanese descent.

The country saw terrorist attacks in the early 1990s, when Iranian-backed Hezbollah (search) operatives struck the Israeli Embassy and a Jewish cultural center in separate bombings that killed scores.

But any move to give the country's military a higher profile in internal security would likely serve as a reminder of the military dictatorship, which lasted from 1976 to 1983, which employed torture and killings of dissidents. Subsequent government figures put the number of missing at the hands of the junta at 9,000; human rights groups put it as high as 30,000.

The U.S. government nevertheless provided Buenos Aires with military assistance during that time. Since it returned to democracy, Argentina has sent troops on peacekeeping operations worldwide, and, in addition to the troops in Haiti, the country has 320 peacekeepers in Cyprus and more than 170 in Kosovo.

It is the only country in Latin America that holds "major non-NATO ally" status with the United States, exempting it from certain sanctions.

Relations have further cooled since 2002, when Argentina defaulted on international loans and its economy collapsed. Populist Nestor Kirchner (search) emerged as the president after the political upheaval that followed, and Argentina joined other countries in South America that strongly opposed the U.S.-led war in Iraq.