Hamas on Friday rejected Israel’s demand that it free an Israeli soldier in return for lifting the blockade in Gaza Strip.

Hamas leader Mousa Abu Marzook accused Israel of backtracking on a truce agreement. He said that the soldier Gilad Shalit would be freed in return for hundreds of Palestinian prisoners held captive in Israeli jails. Shalit was captured in June 2006 near the Gaza boundary fence.

Israel’s security cabinet had on Wednesday agreed to maintain the blockade until Shalit was released. The soldier is said to be alive but his whereabouts are unknown.

US Senator John Kerry met Israeli and Palestinian officials on Friday after a trip to Gaza, where he was given a letter reportedly for President Barack Obama from Hamas.

The chairman of the powerful Senate foreign relations committee was to hold talks with Israeli President Shimon Peres and then meet the Palestinians before flying to Syria on Saturday.

The President’s office said Peres and Kerry would discuss “the regional reality in the wake of the war in Gaza” among other things.

“A letter addressed to Obama was left at the gate of our offices in Gaza; it is believed to be from Hamas,” said Christopher Gunness of UNRWA, the agency for Palestinian refugees. Asked about the contents of the letter, Gunness said, “We are very polite at UNRWA, we don't open other people’s mail.”

However, Hamas later denied having passed on a letter for Obama. “Hamas denies having given a letter to John Kerry,” spokesman Fawzi Barhum told AFP in the Gaza Strip.