President Barack Obama will host his counterpart from Colombia in February to stand with his staunchest ally in South America as peace talks with leftist rebels enter a critical phase that may require additional U.S. support.

Officials said the Feb. 4 meeting announced Tuesday is intended to commemorate 15 years since the start of the U.S.-funded Plan Colombia, which is credited with forcing the Revolutionary Armed Forces of Colombia, or FARC, to enter peace talks in 2012.

In thanking Obama for the invitation, President Juan Manuel Santos said he hopes he'll be joined at the White House by two conservative predecessors, Alvaro Uribe and Andres Pastrana, who laid the framework for the battlefield success.

But their presence is unlikely, as both are fierce critics of Santos and accuse him of being too lenient in talks with rebel leaders behind scores of war crimes.

A major breakthrough in the Cuba-based talks came in September when negotiators announced a framework for rebels who confess their crimes to avoid jail time and instead serve out sentences helping war-torn rural communities rebuild.

While momentum toward a deal is building fast, several obstacles remain, two of which are in Obama's hands: the FARC's demand that the U.S. stop classifying the insurgency as a foreign terrorist organization and release from jail a veteran rebel known by his alias Simon Trinidad who is serving out a 60-year sentence on drug charges.

Since the start of Plan Colombia, both Republican and Democrat administrations have provided more than $10 billion in aid to Colombia, much of it to combat cocaine trafficking that for decades has fueled political violence.