Only 1,000 tonnes of the 7,000 tonnes of humanitarian aid shipped to war-ravaged Gaza from Cyprus have been distributed because of insecurity, US aid officials said on Wednesday.

The remaining 6,000 tonnes was on shore in secure conditions but has yet to be distributed because of an upsurge in violence and looting, the officials said.

The sea corridor linking Cyprus with the Gaza Strip opened in March, delivering a fraction of the basic supplies needed to sustain the Palestinian territory's 2.4 million people.

The maritime aid route has faced obstacles, including security concerns at a US military-built pier and the distribution of aid upon arrival.

"I have never seen a more challenging or complex environment for the humanitarian community to work," said USAID's Doug Stropes.

"There is currently a security review on the lawlessness and gang activity," he said, referring to information received from partners on the ground.

Cyprus Foreign Minister Constantinos Kombos said that despite the challenges, the aid effort to Gaza would continue.

"There is a constant flow of vessels and sending to the other side," he said.

"There are of course certain challenges, challenges that relate to everything going on in Gaza, but we continue the effort.

"It is not going to be an easy task.

"We are, after all, operating in what is a war zone and we are doing everything we can in cooperation with our partners to ensure that this has an impact on the daily lives of people on the ground."

The US ambassador to Cyprus, Julie Fisher, said Washington was committed to exhausting "every possible avenue to alleviate the suffering of the Palestinian people who are facing catastrophic levels of food insecurity".

The Gaza war began with Hamas's October 7 attack on southern Israel that resulted in the deaths of 1,195 people, mostly civilians, according to an AFP tally based on Israeli figures.

The militants also seized about 250 hostages, 116 of whom remain in Gaza although the army says 42 are dead.

Israel's retaliatory offensive has killed at least 37,718 people, also mostly civilians, according to data from Hamas-run Gaza's health ministry.