A Norwegian trauma surgeon and activist who helped provide life-saving medical care during this summer’s 100-day war in Gaza has said he will defy an Israeli ban on his return.

Chief surgeon Mads Gilbert, 67, has spent 15 years treating patients in Gaza and spent 51 days in Shifa hospital earlier this year treating many of the 11,000 Palestinians who were wounded in the war between Hamas and Israel.

When he returned last month to try and enter Gaza via the Erez crossing in Israel he was denied entry indefinitely.

The Israeli government now says Gilbert is banned from entering Gaza for security reasons. The Norwegian embassy in Tel Aviv has taken up Gilbert’s case on his behalf after he was refused entry in October.

“When we came back to the Erez border station the Israeli soldiers told me I was not allowed to go into Gaza,” he told media.

“I had a valid permit for multiple entries, an invitation from the Palestinian Ministry of Health and a recommendation from the director at my hospital.”

In a written statement, Norway’s Secretary of State, Bard Glad Pedersen, said: “From the Norwegian perspective, we have raised Gilbert’s exclusion from Gaza and asked Israel to change their decision. The humanitarian situation is still difficult and there is a need for all health workers.”

Norwegian authorities confirmed Gilbert had been banned “indefinitely” by Israel.

Gilbert is a vocal critic of the Israeli occupation of Palestinian territories and the blockade on the Gaza Strip. Photos and television footage of Gilbert in his light green surgical wear in Gaza’s Shifa hospital treating Gazans wounded and dying were broadcast internationally and often daily during the course of the war between Hamas and Israel.

He vowed he would fight any restrictions placed on his movements by Israel.

“I have never violated Israeli law, never been arrested and never lied.”

In July Gilbert wrote a statement from Shifa hospital at the height of the fighting that was published widely. He described in graphic detail people that had been “maimed and torn apart”.

He described the patients he treated as being innocent civilians. “We still have lakes of blood on the floor in the emergency room, piles of dripping blood soaked bandages to clear out. Cleaners are everywhere swiftly shoveling the blood and discarded tissues, hair, clothes, cannulas, and the leftovers from death – all taken away to be prepared again to be repeated all over.”

He called on readers to force Israeli to stop its attacks on Gaza. Dr Gilbert gave a similar account during live television interviews.

Gilbert is defiant in responding to the ban and resolved to make a return to Gaza in the near future.

“It is completely unacceptable to restrict the movement of humanitarian personnel – much needed in Gaza now after the last bombardment,” he said.

“I will not be stopped from returning to Gaza to do medical work. There are different attempts going on to conceal the reality on the ground for the good people of Gaza – this is one of them – and we must persist in resisting attempts to shutdown Gaza from the world.

“The first precondition for the recent ceasefire was to ease the siege,” he said. “It has not been eased. This attempt to stop medical personnel entering Gaza is a tightening of the siege – this, again, is totally unacceptable.”

During the war, Gilbert charged that Israel was committing “state terrorism at the highest levels”.

An Israeli foreign ministry spokesman, Paul Hirschson, replied Dr Gilbert was “not on the side of decency and peace and he’s got a horrible track record. I wouldn’t be surprised if his acquaintances are among the worst people in the world.”

During Israel’s 51-day military operation in Gaza over 2,000 Palestinians were killed – mostly civilians, and 70 Israelis were killed, mostly soldiers. A ceasefire deal was struck at the end of August to bring an end to fighting. Dr Gilbert said the agreement had not been upheld and called his ban on entering Gaza as further evidence a blockade on the coastal enclave was no closer.