Saudi Arabia and its other Gulf allies are set to open their airspace and maritime borders, ending a three-year old blockade on Qatar in a landmark agreement that is likely to be signed later on Tuesday.

Kuwaiti Foreign Minister Ahmad Nasser Al-Sabah said on state TV on Monday that Saudi Arabia and Qatar had agreed to open their borders this week.

"Based on (Kuwait's ruler Emir) Sheikh Nawaf's proposal, it was agreed to open the airspace and land and sea borders between the Kingdom of Saudi Arabia and the State of Qatar, starting from this evening," Al-Sabah said.