The government could buy some 500,000 hectares (1.23 million acres)during the administration of leftist President Gustavo Petro, which runs until 2026, Lopez said, far less than the 3 million hectares Petro himself suggested in September.

The president's comments led to market volatility due to the potential impact buying such a quantity of land would have on Colombia's finances.

The cost of the 500,000 hectares could come in at 10.2 trillion pesos ($2.11 billion), Lopez forecast, about half of what the government's tax reform recently passed by Congress aims to raise annually.

"I would be happy (with hitting 500,000 hectares)," Lopez told Reuters in an interview. "I know that the president probably wouldn't be happy but I would, because I know how difficult this is going to be."

Nobody will help the government buy land, Lopez said, adding the pace of land purchases will be set by the president and the country's finances.

Colombia borrowed heavily amid the coronavirus pandemic, prompting ratings agencies to cut its sovereign debt rating from investment grade to junk.

Colombia's fiscal framework suggests it will finish 2022 with public debt equivalent to 56.5% of gross domestic product and fiscal deficit of 5.6% of GDP, before it drops to 3.6 % next year.

Agrarian reform is a key point of the 2016 peace deal signed between the Colombian state and the now-demobilized Revolutionary Armed Forces of Colombia (FARC) guerrillas.

The process will need thorough analysis with teams of lawyers to avoid buying land where people were displaced by illegal armed groups or which does not comply with productivity requirements, Lopez added.

"As I've said, we're going to carry out a very intricate operation," she said.