Chief negotiator Gustavo Bell returned on Colombia earlier this month after the expiry of a previous ceasefire spurred a wave of rebel attacks on security forces and oil infrastructure.
Four members of the security forces were killed, one oil worker was kidnapped, more than 20 alleged ELN members were arrested over the past 10 days.
Under international pressure, the ELN decreased the intensity of attacks after the January 10 wave.
Santos announced he agreed to seek a new ceasefire after demanding the guerrillas cease all hostilities.
In response to the call of the United Nations, Gustavo Bell will travel to Quito to explore the possibility of a new ceasefire that allows the continuation of talks with the ELN.
President Juan Manuel Santos
On his return, Bell will meet with representatives of the ELN and guarantor countries that have been accompanying the talks that began in February last year.
While initially rejecting the possibility of a ceasefire during the talks, Santos has now reversed his position and rejects the possibility of peace talks without a ceasefire.
The bilateral ceasefire with the ELN was the first since the Marxist group’s formation in 1964 and took place in the first year of a peace process with 14,000 disarmed FARC guerrillas.
The truce was marred by violence incidents targeting civilians by guerrillas, police and dissident members of demobilized groups FARC and the AUC.