Updated

A United Nations report said Wednesday that cultivation of the plant used to make cocaine has reached an all-time high in Colombia, adding pressure on President Ivan Duque to resume an aerial spraying program suspended by his predecessor over health concerns.

Annual data released by the U.N. indicates Colombian coca cultivation increased 17 percent to 171,000 hectares (660 square miles) in 2017. This could mean cocaine production grew by an estimated 31 percent to 1,379 metric tons.

The findings, based on satellite imagery and on-the-ground verification, track with those of a White House report earlier this year.

Colombia is a top U.S. ally in Latin America, but the boom in coca production has tested relations between the two nations. U.S. President Donald Trump recently threatened to decertify Colombia as a partner in the war on drugs if it failed to reverse course.

Duque, when he took office last month, identified the coca surge as a national security risk. Officials have since said they want to resume aerial spraying of herbicide that was ended by former President Juan Manuel Santos three years ago amid peace talks with leftist rebels who were heavily involved in the drug trade.

But jumpstarting the program will require taking on a constitutional court ruling that places strict limits on the use of the herbicide glyphosate. Some drug policy experts have also questioned the wisdom of bringing back the costly program when drug production has migrated to areas off-limits to spraying, like national parks.

"Our goal is to show dramatic results in the next four years," Duque said Wednesday after a meeting with his top military command.

One solution under study by military officials is the use of drones, which fly at a lower altitude, preventing chemicals from drifting and destroying legal crops.

But longer term, experts say, there is no substitute for the costlier, more dangerous and time-consuming work of building up state institutions in long-neglected rural areas and providing peasant farmers with economically viable legal alternatives.

As in years past, the bulk of coca production in 2017 was concentrated in Colombia's southern region. Coca cultivation in Narino province alone surpassed 45,735 hectares — more than the entire amount found in Peru, the world's second-largest cocaine supplier after Colombia.

The U.N. said the increased supply has so far not resulted in any major drop in cocaine prices globally, although purity levels have risen considerably.