Updated

U.S. Secretary of State Rex Tillerson says he is encouraged by Colombia's progress in reducing the amount of coca grown in the South American nation.

But President Donald Trump's top diplomat also cautioned during his visit to Colombia on Tuesday that "we need to see the results."

In a joint appearance with President Juan Manuel Santos, Tillerson said the U.S. shares a responsibility in combating the drug trade and will continue to support Colombia's efforts.

His remarks come months after Trump threatened to decertify Colombia as a partner in the war against drugs unless the nation reverses a record surge in cocaine production.

A White House report found cultivation of the plant used to make cocaine rose to levels unseen in nearly two decades of U.S. eradication efforts in 2016.