The bilateral relations between the United States and Colombia revolve around two issues that, in order of priority, are drug trafficking and the situation in Venezuela. In terms of drug trafficking, Colombia is under pressure to show results as studies from the US and the UN show a significant growth in illicit crops, which serves as a proxy for the estimated amount of cocaine making its way to Europe and the United States. In response to this issue, the Colombian government has proposed restarting aerial fumigation of illicit crops using glyphosate. The government plans to use drones to fumigate, an initiative that has not yet begun and is expected to have a strong rejection in rural areas. Duque's priority will be to show progress in the fight against drug trafficking (interdiction, fumigation and fight against criminal groups) ahead of his bilateral meeting with President Trump to be held in Colombia, scheduled for December 2. At their UN meeting in late September, Duque and Trump agreed that Colombia’s seemingly tougher stance on coca crops, as well as its efforts to prohibit recreational use of other drugs such as marijuana, are steps in the right direction.
Venezuela ranks second in the list of bilateral priorities. Trump and some members of the Republican party in Congress have expressed their desire to intervene strongly in Venezuela. The proposal has been echoed in some Colombian political sectors close to Duque including the newly appointed ambassador to the US Francisco Santos, however, the president has insisted that the only viable solution for Venezuela is diplomatic and regional. The growing number of Venezuelan migrants in Colombia, partly a result of the policies of Ecuador and Peru in restricting their passage, has plunged Colombia into the most serious migration crisis in its history.
There is an increasing likelihood that Trump and the Republican party will lose their majorities in mid-term elections on November 6. This will make Trump highly irascible and will prompt him to show strength in the global scenario to counteract a setback in his domestic popularity. This means Trump could escalate his rhetoric, on twitter or otherwise, against Venezuela to improve his electoral prospects, and in the event, the Republicans lose their majority. Therefore it would not be surprising that Trump cancelled his visit to Colombia in this scenario. It is likely that Trump's patience on Venezuela will diminish as the political and economic situation of that country continues to deteriorate. An electoral victory of Jair Bolsonaro in Brazil could generate greater regional gravitas for an intervention in Venezuela and/or greater pressure to force Maduro to resign his position. Regarding drug trafficking, it is likely that the United States recognizes that Duque has just begun his term of office, so the US President will not demand immediate results in terms of eradication targets, but will likely expect to see changes in Duque's policies against narco-trafficking in the next six months to a year.