The United States and major EU nations called Monday for more pressure to get a ceasefire between Hamas and Israel, the French presidency said, as a conflict that has killed more than 1,000 Palestinians rages on.

The leaders of the United States, Germany, France, Britain and Italy "agreed to redouble their efforts to obtain a ceasefire. Pressure must increase to get there," the French presidency said.

Iran's Foreign Minister Mohammad Javad Zarif conducted a hefty round of telephone diplomacy late Sunday to rally support and humanitarian aid for Palestinians in the besieged Gaza Strip.

He spoke with U.N. Secretary General Ban Ki-moon, EU foreign policy chief Catherine Ashton and regional leaders, stressing that the priority was to get food and medical aid into areas worst hit by Israel's military offensive, Iran's official IRNA news agency said.

Thousands of people protested in the Dutch port city of Rotterdam on Sunday against what some labeled Israel's "genocide" in Gaza, media reported.

State broadcaster NOS said as many as 10,000 people took part in the demonstration against Israel's offensive in Gaza, with marchers waving posters reading: "Free Palestine" and "No Dutch support for Palestinian genocide."

U.S. Secretary of State John Kerry is working for Israel and Hamas to agree to further halts in the Gaza bloodshed ahead of Egyptian-led peace talks, an official said Sunday.

Kerry returned to Washington early Sunday after a weeklong mission to the Middle East that failed to reach a permanent ceasefire to stop the 20-day conflict which has killed more than 1,000 people, mostly Palestinian civilians.

Prime Minister Tammam Salam on Sunday ruled out a role for Hizbullah in the ongoing conflict between Israel and Gaza-based Palestinian groups, urging an end to the Israeli “aggressiveness” and “hegemony” in the region.

“If we can put an end to Israeli hegemony and to Israeli aggressiveness in this region, we will put an end to many violence in this region and if we cannot do that, violence will prevail,” Salam said in English in an interview on CNN.

Hizbullah chief Sayyed Hassan Nasrallah has discussed with Progressive Socialist Party leader MP Walid Jumblat the need to elect a president as soon as possible and boost coordination among security agencies, both parties announced on Sunday.

The two leaders held their meeting in the presence of Wafiq Safa, head of Hizbullah's Liaison and Coordination Unit, according to a joint statement issued after the talks.

Israel's Prime Minister Benjamin Netanyahu on Sunday accused Hamas of violating a ceasefire that it had itself called and vowed that Israeli operations in Gaza would continue, as the death toll from 20 days of Israeli bombardment of the Palestinian strip rose to 1,031.

Hamas' belated acceptance of diplomatic calls for a temporary ceasefire was announced several hours after Israel resumed a devastating military assault on the enclave after a pause of more than 24 hours. 

Egypt's army said Sunday it has destroyed 13 more tunnels connecting the Sinai Peninsula to the Gaza Strip, taking to 1,639 the overall number it has laid waste to.

Kataeb Party chief Amin Gemayel stressed on Sunday that the parties that are hindering the presidential elections and obstructing the state are well-known, pointing out that any decision to run for presidency will be announced after consultations with allies.

“Those behind the (presidential) conspiracy are known and the Lebanese know the parties that are causing lack of quorum,” Gemayel said in comment published in the Kuwaiti Seyassah newspaper.

At least 10,000 pro-Palestinian protesters opposed to Israel's military action in Gaza marched through central London for the second week running on Saturday.

A police source estimated the crowds at 10,000, but an Agence France Presse photographer suggested the number could be far higher, forcing the closure of roads around Britain's parliament.