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The Obama administration said Sunday that a key free trade deal with Colombia will be fully enforced next month, an expected but important victory for the U.S. business community, which contends the pact will be an economic boon for America. Obama officials insisted they moved ahead only after the Colombia took steps to halt deadly violence against labor unionists.

President Obama and Colombia President Juan Manuel Santos were expected to hail the agreement at an afternoon news conference. For Obama, it amounted to a chance to shift some focus back to his original mission in Latin America -- creating jobs back home -- amid the distraction of a Secret Service scandal involving prostitutes that all unfolded before Obama arrived.

The news of the trade-deal implementation came as Obama huddled with about three dozen regional leaders in hot and steamy Cartagena as the Summit of the Americas drew to a close.

Throughout his trip, Obama has touted Latin America as a growth region for U.S. businesses in an election-year economic appeal aimed at voters back home.

U.S. unions have opposed the trade deal, saying Colombia still has an abysmal record of violence against labor leaders. Union workers are a core Obama constituency, but have opposed some of his efforts to expand free trade deals, which they believe take jobs away from U.S. companies.

Under the terms of the trade pact, more than 80 percent of industrial and manufactured products exported from the U.S. and Colombia will immediately become duty free, making it cheaper for American businesses to sell their goods to the South American country. More than half of U.S. agriculture exports to Colombia will also become duty free.

In a conference call with reporters, U.S. Trade Representative Ron Kirk said Colombia has taken a number of important steps to implement the "labor action plan" that was a prerequisite for putting the trade deal into place. The plan included enforcing laws recognizing the rights of workers to organize and prosecuting past cases of violence against labor leaders.

"We believe this is an historic step in the development of our relationship with Colombia," Kirk said.

Colombian labor activists complain the Labor Action Plan has been a fig leaf that has not done enough to protect trade unionists in the world's most dangerous country for labor organizing. At least 30 trade unionists were killed in Colombia last year and four so far this year, according to Viviana Colorado of Colombia's National Union School, which tracks the figures.

That is down from 51 killed in 2010.

In October, on the eve of U.S. congressional approval of the trade pact, Human Rights Watch released a study refuting claims by the Obama administration that Colombia is making important strides in bringing to justice killers of labor activists. The study found "virtually no progress" in getting convictions for killings that have occurred in the past 4 1/2 years.

At the news conference, Obama could also face his first questions Sunday about embarrassing allegations of Secret Service personnel cavorting with prostitutes in Cartagena ahead of the president's arrival. The scandal has cast a cloud over the U.S. delegation at the summit, forcing the White House to assert that Obama still has confidence in the agency that protects his life and the Secret Service to offer its regrets for distracting from the summit.

Meanwhile, some of Obama's peers from Central and South America pushed talks on drug legalization, which they believe could help tamp down rampant cartel violence in the region. Decriminalization would be politically unpalatable in the U.S., and Obama has made his opposition known.

Also competing for attention Sunday were widespread demands for the summit's final declaration to specifying that Cuba be included in future hemispheric meetings. The U.S., along with Canada, was staunchly opposed, with officials insisting that communist-run Cuba does meet the summit's democratic standards.

By now, Obama may be used to his foreign trips getting overshadowed by unexpected distractions.

In the past year alone -- in travels to Latin America, to an economic summit in Cannes, France, to Seoul, South Korea and now in Cartagena -- Obama's intended message has been sidetracked, interrupted or even buried by bad timing, miscues or, in the case of the allegations in Colombia, outright scandal.

Eleven Secret Service employees were on administrative leave for misconduct and five service members assigned to work with the Secret Service were confined to quarters amid allegations involving prostitutes and heavy drinking. The Secret Service and the U.S. Southern Command said the misconduct occurred at their hotel in Cartagena before Obama arrived in the Caribbean city on Friday.

Waiters interviewed by The Associated Press described the agents as drinking heavily during their stay.

For Obama, this scandal is particularly piercing because it goes against type.

When his trip to Brazil and Chile in March 2011 was overwhelmed by U.S. bombing over Libya, it displayed strength even as he carried out a military act from abroad. A live microphone in Cannes captured him and French President Nicholas Sarkozy discussing Israeli Prime Minister Benjamin Netanyahu, with Sarkozy confiding he couldn't stand working with the Israeli leader.

But while briefly embarrassing it wasn't wholly revelatory.