Homeland Security chief John Kelly and CIA director Mike Pompeo reportedly flew over Mexican opium fields

Mexican Defense Secretariat/Twitter

US Homeland Security Secretary John Kelly, center, observes opium-poppy eradication operations in Mexico's Guerrero state, July 6, 2017.

MEXICO CITY (AP) - Mexico says U.S. Homeland Security Secretary John Kelly has visited one of the country's most restive states and watched troops destroy opium-poppy fields.

Kelly arrived to Mexico on Wednesday and met with President Enrique Peña Nieto before the Mexican leader departed for France ahead of the Group of 20 summit in Germany.

Kelly, along with CIA Director Mike Pompeo, met with Peña Nieto to discuss approaches to transnational crime, regional security, and economic cooperation.

Arkansas Republican Sen. Tom Cotton, who sits on the Senate select committee on intelligence, was also a part of the meeting.

Peña underscored his government's openness to cooperating with the US to combat organized crime, his office said in a statement.

Mexico's Defense Department said in a statement late Thursday that Kelly accompanied military leaders to the southern state of Guerrero, one of the country's primary opium-producing states.

Mexican Defense Secretariat/Twitter

US Homeland Security Secretary John Kelly, center, with Mexican military officials in Guerrero state, July 6, 2017.

Kelly observed the destruction of five poppy plots via manual eradication as well as aerial spraying. According to Mexican news site Reforma, Pompeo also took part in the flyover with Kelly, and the pair were joined by Mexican Defense Secretary Salvador Cienfuegos and Navy Secretary Vidal Soberon.

In early April, the Mexican military allowed US and UN personnel to observe opium-poppy eradication for the first time in at least a decade.

REUTERS/Henry Romero

A soldier among poppy plants set to be destroyed during a military operation in the Guerrero state municipality of Coyuca de Catalan, Mexico.

The move came after at least a year of efforts by the US military to improve relations with its Mexican counterpart and support eradication efforts.

The Trump administration has emphasized the need to stem the flow of drugs, heroin in particular, from Mexico to the US.

In mid-April, Pompeo said that he and Kelly had presented Trump with some options for addressing narcotic threats in Mexico and Central America.

"I think ... a lot of focus can do some good there, and I think we're going to head down that path," the CIA director said at the time.

Efforts to crack down on opium-poppy cultivation and heroin production may be stymied by unreliable data and the complexity of eradication efforts, however.

Kelly's visit was scheduled to end Friday.