KUALA LUMPUR, Malaysia — The United States welcomes Malaysia's crackdown on human trafficking, but wants to see "results rather than rhetoric" before it can remove the Southeast Asian country from a blacklist, a senior official said Thursday.

Several alleged traffickers, including government officials colluding with them, have been arrested and charged in recent weeks after Malaysia was labeled one of the world's worst offenders in a U.S. State Department report released in June.

The prosecutions were "heartening," Luis CdeBaca, a top State Department official, told reporters at the end of a three-day visit to Malaysia where he met with government officials and aid groups.

But "we are looking for sustainability. We want to make sure that cases are brought (to court) not simply in the interim period," he said.

CdeBaca was appointed in May to head the Office to Monitor and Combat Trafficking in Persons, which coordinates U.S. government activities in the global fight against human trafficking.

"We are looking at results rather than rhetoric," he said. "We are heartened by the tone and desire of the (Malaysian) government to achieve results but in terms of having tangible results that is something we have to continue to discuss."

The U.S. report said Malaysia is a destination and source for women and children trafficked for the purpose of prostitution, and men, women and children used for forced labor. Many of the victims were brought from Myanmar.

CdeBaca said Washington wants to see sustained investigations and prosecutions throughout the year before making its final decision on whether to remove Malaysia from the list in its 2010 report.

This was the third time Malaysia has been singled out for its record on human trafficking. It was first included in the State Department blacklist in 2001 and again in 2007, but was removed last year. Fifty-one other countries are also on the list.

If a country appears on the list for two consecutive years, it can be subject to U.S. sanctions.

CdeBaca said a team of American experts comprising an experienced federal prosecutor, FBI personnel and a victims' specialist will travel to Malaysia in October to help train Malaysian counterparts in enforcement.

He also urged the Malaysian government to work together with NGOs in what he said was a fight against "modern slavery."

Malaysia's Home Minister Hishammuddin Hussein has said the government will do "whatever it takes" to stop the problem, but noted there were many hurdles including a porous border with Thailand.

Activists estimate that hundreds of thousands of people from Myanmar live illegally in Malaysia in addition to 140,000 legal Myanmar migrant workers.