Aid from international bodies has deteriorated after the evacuation of personnel from Libya due to the worsening security situation.
US Africa Command said it had relocated an unspecified contingent of US forces, while India said it had evacuated peacekeepers to Tunisia.
Rebel forces under Gen Khalifa Haftar have advanced from the east with the aim of taking the capital, Tripoli.
The UN-backed prime minister has accused him of attempting a coup and says rebels will be met with force.
Libya has been torn by violence and political instability since long-time ruler Muammar Gaddafi was deposed and killed in 2011.
India’s External Affairs Minister Sushma Swaraj said its full contingent of 15 Central Reserve Police Force peacekeepers had been evacuated from Tripoli because the “situation in Libya has suddenly worsened”.
The Italian multinational oil and gas company, Eni, decided to evacuate all its Italian personnel from the country.
The UN is also due to pull out non-essential staff.
Residents of Tripoli have reportedly begun stocking up on food and fuel