By Nandita Bose and Sofia Menchu

GUATEMALA CITY (Reuters) -U.S. Vice President Kamala Harris said on Monday she had “robust” talks with Guatemalan President Alejandro Giammattei on the need to fight corruption to help deter undocumented immigration from Central America to the United States.

At a news conference with Giammattei, Harris said a U.S. task force would work with local prosecutors to punish corrupt actors in the region.

The Biden administration has identified corruption as an underlying cause of the poverty and violence driving record numbers of Central Americans to go to the United States

In the build up to Harris’ visit to Guatemala, her first official overseas trip, differences of opinion emerged about the fight against graft, with corruption fighters feted by Washington being criticized by Giammattei.

“We had a robust, candid and thorough conversation,” Harris said at the news conference after a three-hour meeting with Giammattei, who said they had discussed U.S. concerns about developments in Guatemala.

“The president and I discussed the importance of anti-corruption and the importance of an independent judiciary,” Harris said. Washington has criticized the removal of a senior judge from Guatemala’s top court, in what Giammattei has argued was a legitimate process.

The corruption task force has been previously floated, but Harris gave more details, saying it will combine resources from the Justice, State and Treasury departments.

Giammattei defended his own record in fighting corruption, saying he had not been accused of wrongdoing and saying graft was not only a problem faced by politicians. The fight against drug trafficking needed to be an integral part of tackling corruption, he said.

On the immigration front he announced a new processing center for migrants sent back from Mexico and the United States, which could increase capacity. He said the focus of the two countries should be on creating prosperity.

Most Guatemalan migrants leave because of poverty, he said, and come from a few rural municipalities. Harris said Guatemalans should not take the dangerous journey north.

“Do not come. Do not come. The United States will continue to enforce our laws and secure our borders,” she said.

“If you come to our border, you will be turned back.”

Democrat Harris responded to questions about Republican criticism that she had not done enough to stem migration in the short term, saying she was working on the ground in Guatemala.

“I’m just focused on that kind of work as opposed to grand gestures,” she said.

The Biden administration on Monday also unveiled details of another task force of prosecutors to combat human smuggling in Central America and Mexico.

U.S. Attorney General Merrick B. Garland said the Joint Task Force Alpha would marshal Justice Department and Homeland Security resources against “the most prolific and dangerous” human smuggling and trafficking groups in the region, according to a statement. It said the group will complement the efforts to build cases against corrupt actors.

However, Washington’s push to tackle “root causes” of migration in El Salvador, Guatemala and Honduras have been undermined by a backlash against anti-corruption bodies the United States considers independent but that local elites say are biased.

Harris will also meet civil society leaders and entrepreneurs in Guatemala and then go to Mexico. Priorities include economic development, climate and food insecurity and women’s issues, White House officials said.

There has been criticism from some officials in Guatemala and Mexico over the timing and thrust of Harris’ mission, with the Mexico talks scheduled on Tuesday, just days after mid-term elections there.

Harris said she discussed sharing COVID-19 vaccines with Guatemala during Monday’s meeting. She confirmed that the United States would supply half a million COVID-19 doses to Guatemala and provide $26 million to fight the pandemic.

(Reporting by Nandita Bose in Guatemala City; Additional reporting by Sofia Menchu in Guatemala CityEditing by Frank Jack Daniel, Sonya Hepinstall and Grant McCool)