Save the Children said an unprecedented number of children in Syria are now battling soaring malnutrition rates.
The two presidents were meeting after a surge in fighting in Syria raised fears of their armies clashing and launched a new migrant crisis.
The announcement comes after a massive assault launched by Syrian government and allied forces on February 18 to retake the enclave, which has been out of regime control since 2012.
The three countries had carried out a wave of pre-dawn missile strikes, hitting targets near Damascus and in Homs province, Western officials said.
The United States is consulting with Britain and France about a joint military response to the attack in Douma that medics and rescuers said left at least 40 people dead on Saturday.
Erdogan said he is extremely worried that some countries confident of their military power are turning Syria into a scene for arm wrestling.
The ambassador cited concerns over measures to enforce the ceasefire and the safe delivery of aid before announcing that he would circulate proposals to amend the draft resolution.
Turkey on Thursday dismissed France's claims over civilian losses in Ankara's ongoing Syria operation, labelling them "unfortunate" and "baseless" accusations.
The US-led anti-jihadist coalition carried out strikes in "self-defense" against forces loyal to Syrian President Bashar al-Assad, leaving an estimated more than 100 dead.
As soon as Turkish warplanes began bombing raids over Afrin on Saturday, terrified residents of the Syrian Kurdish enclave dashed to take cover in the cellars of their homes.
The Trump-Macron meeting "will focus on Syria and counter-terrorism topics," the official said who spoke on condition of anonymity.
US cruise missiles were fired at a Syrian govt airbase and Trump said that the strikes were carried out in a response to a chemical attack on civilians.