The European Union's foreign policy chief has asked Israel not to take military action in Rafah in the southern Gaza Strip, where more than 1.4 million people are taking shelter.

Josep Borrell said in a social media post on Saturday that an offensive in Rafah would "worsen an already catastrophic humanitarian situation."

International concerns are growing as Israel continues airstrikes on Rafah and appears set to launch a ground assault, saying it seeks the destruction of Hamas.

International human rights groups and NGOs said in a joint statement that they are "appalled by the harrowing developments in Rafah."

They also said, "If Israel launches its proposed ground offensive, thousands more civilians will be killed," and called for the military plan to be stopped immediately.

On Saturday, Israeli Prime Minister Benjamin Netanyahu reiterated a pledge to go ahead with the offensive. He said that whoever is telling Israelis not to operate in Rafah is essentially telling them to lose the war.

Many people are sheltering in Rafah as their last resort after they fled from northern and central Gaza.

A man who evacuated there with his family from the northern city of Gaza said they are living in a tent in the harsh cold.

He added that he only hopes for the safety of his family, but there is no safe place to go amid the conflict.