Pro-Palestine protests and counter-protests have been the center of attention in recent weeks

Joe Biden broke his silence Thursday on the student protests against Israel's war with Hamas but the US president faces a difficult balancing act to avoid hurting his reelection chances against Donald Trump.

After months of stop-start negotiations, Hamas has sounded an optimistic tone about the latest hostages-for-ceasefire proposal, raising hopes an agreement may soon be reached.

Officers also detained several people at Fordham University in New York and cleared an encampment set up inside a school building, officials said, and law enforcement were on standby at Columbia University across town after mass arrests the previous evening.

Netanyahu is Israel's head of government, while the country's president -- a role which is largely ceremonial -- is Isaac Herzog.

Washington has heightened pressure on all sides to reach a ceasefire -- a message pushed by Blinken, who was on his seventh regional tour since the Gaza war broke out in October.

Israeli Prime Minister Benjamin Netanyahu reportedly raised the issue with US President Joe Biden in a call at the weekend.

Overnight protesters occupied a campus building, barricading themselves inside while several others formed a human chain outside, according to a video posted on social media.

Blinken flew to Amman after talks with Gulf Arab leaders in Riyadh, part of his seventh tour of the region since the October 7 attack by Hamas on Israel.

The wave of demonstrations began at Columbia University in New York but they have since spread rapidly across the country.

A senior Hamas official said Sunday that the Palestinian group had no "major issues" with the most recent truce plan.

Both sides have stepped up attacks this week, with Hezbollah increasing rocket fire and Israel saying it had carried out "offensive action" across southern Lebanon.

The UK on Thursday joined the United States and Canada in announcing a fresh set of sanctions against Iran's drone and missile industries after its recent attack on Israel.

Police have carried out large-scale arrests in universities across the country, at times using chemical irritants and tasers to disperse protests over Israel's war with Hamas.

Fears are rising that Israeli Prime Minister Benjamin Netanyahu will soon follow through on repeated threats to send troops into the southern Gazan city of Rafah, where 1.5 million people are sheltering, many in makeshift encampments.

Tlaleng Mofokeng, the United Nations special rapporteur on the right to health, accused Israel of treating human rights as an "a la carte menu".

The protests, which began last week at Columbia University with a large group of demonstrators establishing a so-called "Gaza Solidarity Encampment" on school grounds, have spread to other campuses, including Yale, MIT and others.

Netanyahu, who threatened action "in the coming days" without elaborating, has repeatedly said Israel will launch a ground assault on Rafah despite international concern for civilians who have taken refuge in the southern Gazan city.

Qatar's warning that it was reassessing its role as a mediator between Israel and Hamas has raised concerns about the prospects for a ceasefire and the return of hostages.

Air defense systems over several Iranian cities were activated, state media reported, after the country's official broadcaster said explosions were heard near the city of Isfahan. There had been no reaction from Israeli or Iranian officials to the overnight strikes and the extent of the damage remained unclear.

Turkish President Recep Tayyip Erdogan said Wednesday he would host a leader of Palestinian militant group Hamas, Ismail Haniyeh, in Turkey this weekend.

The United Nations Security Council will vote Thursday on the Palestinians' application to become a full UN member state, several diplomatic sources have told AFP.

Traders were also digesting figures showing Chinese expansion easily beat expectations in the first three months of the year but retail and industrial data came in well below par, suggesting leaders have much work to do to kickstart growth.

During six months of war between Israel and Iran-backed militant group Hamas in Gaza, Iran's proxies around the region have stepped up attacks on Israel and its allies, saying they are acting in support of Palestinians in Gaza.

The US goal since the start of the latest round of conflict between Israel and Hamas six months ago has been to prevent it from spiraling into a broader regional conflict, and Washington is keen to lower the temperature in the region.

However, while Israel called the attack -- which Tehran said was in response to a strike on its Syrian embassy -- an escalation of hostilities, analysts said there was hope among traders that the crisis could be contained.

World powers have urged restraint after Iran late Saturday launched more than 300 drones and missiles at Israel, though the Israeli military has said the vast majority were intercepted.

With global outrage over the toll inflicted by the six-month-old war growing, Biden rebuked Israeli Prime Minister Benjamin Netanyahu's handling of the conflict and reiterated the need for a ceasefire.

Six months into the bloodiest Gaza war, Qatari, Egyptian and US mediators have proposed another temporary ceasefire, according to a Hamas source.

Israel kept up the pressure, warning that it was ready for future military operations against Hamas in Gaza's far-southern city of Rafah, the last area so far spared a ground invasion.