LONDON - An alliance of 13 major aid groups including Doctors Without Borders (MSF), Amnesty International and Oxfam has urged world leaders to push for a ceasefire in Gaza after one month of war between Israel and Hamas.

The organisations "call on French President Emmanuel Macron and heads of state... to do everything in their power to obtain an immediate ceasefire," they said in a statement, one day before a humanitarian conference on the Gaza Strip is due to be held in Paris.

Other priorities should include "concrete measures to free civilian hostages and protect all civilian populations, guaranteeing entry of humanitarian aid to Gaza and respecting international humanitarian law," the groups said.

As well as MSF, Amnesty and Oxfam, the signatories also include Action Against Hunger, the Norwegian Refugee Council (NRC) and the International Federation for Human Rights.

"We are getting increasingly desperate appeals for protection and aid from our humanitarian workers inside the locked-down Gaza Strip," NRC chief Jan Egeland said in the statement.

"It is unacceptable that there is still no humanitarian ceasefire, no humanitarian corridor and no end to the suffocating siege" of the enclave, he added.