(Bloomberg) -- President Donald Trump said he’s holding off -- at least for now -- on a proposal to classify Mexican narcotics cartels as terrorist organizations, adding that he’s doing so as a favor to Mexico’s president.

“All necessary work has been completed to declare Mexican Cartels terrorist organizations,” Trump tweeted on Friday night. “Statutorily we are ready to do so.”

“However, at the request of a man who I like and respect, and has worked so well with us, President Andres Manuel @LopezObrador we will temporarily hold off this designation and step up our joint efforts to deal decisively with these vicious and ever-growing organizations!”

Trump’s Twitter post appeared as talks with Mexico’s government over a new U.S.-Mexico-Canada free-trade agreement had reached a crucial stage.

Lopez Obrador’s top trade negotiator, Jesus Seade, remained in Washington on Friday in an attempt to resolve final details with the Trump administration.

The proposal to designate the drug crews as terrorist groups emerged from the outrage over the killing early last month of nine members of a Mormon family with dual American-Mexican citizenship in an attack by cartel gunmen in northern Mexico.

Key administration officials are in favor of the policy, according to people familiar with the matter.

Under that plan, the State Department would be allowed to designate cartels as Foreign Terrorist Organizations, putting them in the same category as Islamic State and Iran’s Islamic Revolutionary Guard Corps.

Trump said in a tweet after the attack that it was time “for Mexico, with the help of the United States, to wage WAR on the drug cartels.

Trump appeared to refer to Mexico’s drug cartels during a news conference Tuesday in London, where he was attending a NATO summit: “We’ll be looking at other forms of terror. We’ll be looking at other countries. We’ll be looking at countries that are aggressive, and not just one particular part of this world.”

To contact the reporter on this story: John Harney in Washington at jharney2@bloomberg.net

To contact the editors responsible for this story: Michael Shepard at mshepard7@bloomberg.net, Kevin Whitelaw

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