Medical charity Doctors Without Borders (MSF) has pulled out of a UN-backed World Humanitarian Summit, saying the gathering would fail to pressure governments that are denying basic help to victims of conflict and disease.
"We no longer have any hope that the (summit) will address the weaknesses in humanitarian action and emergency response, particularly in conflict areas or epidemic situations," MSF said in a statement Wednesday.
It charged that the summit, due to take place in Istanbul on May 23-24, would not address "serious gaps" in the response to the recent Ebola epidemic and the "serious restrictions placed by some states on humanitarian access, denying people basic services".
The first meeting of its kind is expected to gather around 45 heads of state and government as well as UN agencies and non-governmental organisations to brainstorm about global humanitarian action.
"We can no longer see how the (summit) will help the humanitarian sector to address the massive needs caused by continuing violence against patients and medical staff in Syria, Yemen and South Sudan," MSF said.
The charity also cited the plight of "civilians intent on fleeing being blocked at borders in Jordan, Turkey and Macedonia (and) the inhumane treatment of refugees and migrants desperately trying to find safe haven in Greece and Australia."
Noting that it had been "significantly engaged" in 18 months of consultations ahead of the event, MSF said: "With regret, we have come to the decision to pull out of the summit."
It said it feared the summit would fail "to reinforce the obligations of states to uphold and implement the humanitarian and refugee laws which they have signed up to".
MSF, one of the world's leading emergency aid providers, has increasingly become a victim of conflict itself.
Last year alone, 75 hospitals managed or supported by the charity were bombed, the charity said without elaborating.
Just last week, the bombardment of the MSF-supported Al-Quds hospital in the divided northern Syrian city of Aleppo left at least 55 people dead, according to the latest toll from the charity.
"The air strikes first hit buildings neighbouring the hospital, then the hospital itself as the wounded were transferred there," MSF said in a separate statement on Wednesday.
"Al-Quds is the main paediatric referral hospital in Aleppo, and those killed include six staff members, including one of the last paediatricians in the city."
The 1999 Nobel peace laureate is also locked in a war of words with the United States military after US planes bombed an MSF hospital in Kunduz, Afghanistan, last September, killing 42 people.
An investigation by the US military last week concluded that the troops targeted the facility by mistake and will not face war crimes charges.
MSF has branded the air strike a war crime.