The Hamas rulers of Gaza on Sunday slammed US Secretary of State John Kerry for urging the Turkish prime minister to delay a visit to the Palestinian territory.

Hamas spokesman Sami Abu Zuhri accused Kerry and Palestinian president Mahmud Abbas -- who met in Istanbul earlier in the day -- of "collusion in a bid to maintain the (Israeli) blockade on Gaza."

Kerry met separately in Istanbul with Turkish Prime Minister Recep Tayyip Erdogan and Abbas, and told reporters he had asked Erdogan to wait for the "right conditions" before going ahead with a planned visit next month to Gaza.

"We have expressed to the prime minister that it would be better to delay (the visit to Gaza)," Kerry told reporters.