The aid agency said in a statement on Thursday that intensified fighting for control of Tripoli is turning densely-populated residential areas of Tripoli into "battlefields".
Hospitals, it said, are struggling with chronic shortages of medical supplies amid power outages and weakened water pumping stations, Presstv Reported.
"The humanitarian situation in and around Tripoli has deteriorated sharply over the past three weeks," the ICRC said.
"It is crucial that hospitals, medical facilities, health staff and vehicles transporting the wounded are allowed to carry out their activities safely."
Elsewhere in the statement, the agency said thousands of people have been displaced by clashes in the violence-wracked region.
"More than 30,000 people are said to have fled their homes and are sheltering with relatives or in public buildings," ICRC) said of a figure which the United Nations says has risen to almost 35,000.
Youness Rahoui, the head of the ICRC office in Tripoli, said it was becoming "increasingly dangerous for medical workers to retrieve the wounded, with mounting reports of indiscriminate shelling".
The 75-year-old Haftar who enjoys the loyalty of a group of armed militia and backing from Saudi Arabia, the United Arab Emirates and Egypt has taken upon himself to protect the government in the eastern city of Tobruk.
Armed forces and militia loyal to the UN-recognized Government of National Accord (GNA), led by Prime Minister Fayez al-Sarraj, have been fighting back.
According to the latest casualty toll from the World Health Organization, at least 278 people have been killed and more than 1,300 wounded in the clashes since the offensive began.
Libya has been the scene of increasing violence since 2011, when longtime dictator Muammar Gaddafi was toppled from power after an uprising and a NATO military intervention.
His ouster created a huge power vacuum, leading to chaos and the emergence of numerous militant outfits, including the Daesh terrorist group.