"After an 8,000km journey, nearly one month on the road and a day and a half on the Egyptitan side of the Rafah border, the Lifeline for Gaxa convoy finally made it into the Gaza Strip. It was a remarkable scene."
The convoy is led by George Galloway, a British member of parliament.
"Galloway has been heavily criticised and there were a lot of sceptics saying this could simply not be done. Today, George Galloway and 300 volunteers who gave up a month of their lives to help the people of Gaza proved all of them wrong," Baer said.
The passage of the convoy through Egypt had been controversial.
The convoy was pelted with stones and vandalised in the Egyptian town of El-Arish, 45km south of the Rafah border crossing, before being cleared to enter Gaza.
'Overwhelmed with happiness'
As he entered Gaza, Galloway said he was "overwhelmed with happiness".
"I have entered Palestine many times but the most emotional of these is after the 22-day genocidal aggression against the Palestinian people," he said.
Galloway said that he planned to meet "the heroes of Palestine's resistance, the government of Palestine, the people of Palestine".
The convoy comprising 110 vehicles has brought aid supplies valued at $1.4m.
Israel's Gaza offensive, which it said was aimed at stopping rocket and mortar attacks by Palestinian fighters, devastated the Gaza Strip. More than 1,300 Palestinians were killed and thousands of homes were destroyed in the assault which ended in January.
Israel and Egypt have sealed Gaza off from all but limited humanitarian aid since Hamas seized full control of the territory in June 2007 after pushing out forces loyal to Mahmoud Abbas, the West Bank-based Palestinian president.