(Writes through with more details of meeting)
By Arshad Mohammed and Julien Ponthus
PARIS, July 26 (Reuters) - U.S., European and regional powers seeking to mediate an end to the conflict in Gaza called on Israel and Hamas on Saturday to extend their 12-hour ceasefire in a bid to win time and discuss each side's grievances.
U.S. Secretary of State John Kerry has pushed efforts to end 19 days of conflict in which 940 Palestinians, many of them civilians, have been killed. He met counterparts from Europe and Qatar and Turkey - prime interlocutors with Hamas - at French-hosted talks in Paris.
"All of us call on the parties to extend the humanitarian ceasefire that is currently underway," French Foreign Minister Laurent Fabius said after the meeting, which also included the foreign ministers of Britain, Germany and Italy.
"All of us want to obtain, as quickly as possible, a durable, negotiated ceasefire that responds both to Israeli needs in terms of security and to Palestinian needs in terms of of the social-economic development (of Gaza) and access to the territory of Gaza," Fabius said.
The ministers, along with senior EU diplomat Pierre Vimont, met on the same day that Israel began a 12-hour ceasefire during which it said it would press on searching for tunnels used by militants. The Islamist group Hamas, which rules Gaza, said all Palestinian factions would abide by the brief truce.
The United States refuses to deal with Hamas because it regards the Palestinian faction as a terrorist group.
"The necessity right now is to stop the loss of life," British Foreign Secretary Philip Hammond told reporters.
"And we stop the loss of life by getting this ceasefire to roll over for 12 hours, 24 hours or 48 hours - and then again until we have established the level of confidence that allows the parties to sit round a table to talk about the substantive issues."
Israel on Friday rejected international proposals for an extended ceasefire, a government source said. Kerry said no formal proposals had been put forward but acknowledged there were still disagreements on the terminology to be used.
"For now the agenda is about getting the ceasefire extended without further preconditions...Once we start going into the demands of the different parties, and the underlying grievances, we run into problems," Hammond noted.
German Foreign Minister Frank-Walter Steinmeier said a ceasefire would only last if Gaza "no longer serves as weapons depot for Hamas and living conditions of the people improve". (Reporting by Arshad Mohammed, Mark John and Henri-Pierre Andre; editing by Michel Rose and Angus MacSwan)