(CNN)-- "Our health delivery system is under stress. The international community couldn't respond quickly," Johnson Sirleaf told CNN's Nima Elbagir in an interview.
Liberia is one of three nations, including Guinea and Sierra Leone, at the center of the deadliest outbreak of Ebola in history. More than 1,500 people have died from the highly infectious virus since March.
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The World Health Organization has confirmed more than 3,000 cases and says the outbreak is still accelerating across West Africa.
Johnson Sirleaf also extended the stay-at-home order for all nonessential government employees for another month on Monday, underscoring the still dangerous health conditions the Ebola virus is causing in the country.
The order went into effect on July 30.
A statement on the President's website said the order is still necessary as efforts to contain the spread of the often fatal virus continue.
But Johnson Sirleaf sounded hopeful. She said conditions are slowly improving and that the world is responding to the epidemic, realizing the catastrophe that could unfold if the virus were to spread beyond Africa's borders.
In a positive sign over the weekend, the quarantine on the Township of West Point in the capital city of Monrovia was lifted on Saturday.
Johnson Sirleaf ordered the quarantine lifted "based on the advice of authorities of the Ministry of Health and Social Welfare, as well as consultations with local and international partners," according to the online statement.
She explained that "the residents' cooperation and support over the period heightened the decision to lift the embargo."
But the President also warned a bigger response is still needed to prevent the spread of the infectious virus and contain the threat.
"People now don't see this as a Liberia or West Africa crisis. It could easily become a global crisis."
Johnson Sirleaf said the solution is for the global community to work in partnership with the affected nations to help them fight Ebola.
"We need that hope, we need that assistance. We need for the Liberians to know that this war can be won," Johnson Sirleaf said.
The West African nation of Senegal confirmed its first Ebola case last week, one week after closing its border with Guinea.
Senegal is the fifth country in the region to report the Ebola virus.