Israeli Prime Minister Benjamin Netanyahu has defended the use of force on the Gaza border after Israeli snipers killed scores of Palestinians and wounded thousands more.

Today 35,000 protesters rallied against the US Embassy opening in Jerusalem as tear gas and sniper fire rained down.

Every country has the obligation to defend its borders,' Netanyahu said on Twitter.

'The Hamas terror organisation declares its intention to destroy Israel and send thousands to break through the border fence in order to achieve this aim. We will continue to act firmly in order to defend our sovereignty and our citizens.' 

It comes after a 14-year-old was among 55 shot dead along the Gaza border on what is already the deadliest single day in the Israeli-Palestinian conflict since a 2014 war between the Jewish state and Gaza's Islamist rulers Hamas.