Speaking after talks with President Ellen Johnson Sirleaf, Lagarde praised Liberia for its hard work in battling the deadly virus.
It became the first of the three West African countries ravaged by the worst Ebola outbreak on record to declare itself free of the disease.
Over 11,000 people have died in West Africa since the epidemic erupted more than 18 months ago. Liberia has been hardest hit, with over 4,800 deaths.
The IMF provided around $130 million in new financing and debt relief for Liberia during the crisis, Lagarde noted.
“Stay the course in the direction of improving the economy of Liberia," she told a news conference. "You have the road map, you have a plan and we want to cooperate."
Low commodity prices are hitting Liberia's export revenues.
“That makes your massive effort of conducting democracy and growth in a post-conflict, post-epidemiological environment even much difficult,” Lagarde said.
Liberia was declared free of the Ebola virus for a second time on Sept. 3, entering a 90-day period of heightened surveillance.
The country was declared Ebola-free in May but more cases appeared in late June, probably via transmission from sexual contact as the virus can survive in semen well beyond the usual 21-day incubation period.(clued from Reuters)