JERUSALEM (AFP) - A strike at Israel's foreign ministry could make Pope Francis's first trip to the Holy Land, set for May, "impossible," an Israeli diplomat said on Friday.

"Imminent planned visits by foreign leaders, including (British Prime Minister) David Cameron next week or the Pope in May, will be complicated, and perhaps impossible" because of the strike which began Tuesday, Mr Yigal Palmor told AFP.

"The leaders could come as tourists, but diplomats will not take care of logistics, protocol or the political dimension of these visits," said Mr Palmor, who spoke as an employee and not in his capacity as ministry spokesman.

The Vatican said there were no plans to cancel the trip but confirmed the strike could result in "complications."

"An ongoing strike is posing a problem, and is likely to cause complications in preparing for the trip," Vatican spokesman Federico Lombardi told AFP.

"There's nothing more to it."

Pope Francis announced in January that he would make his first trip to the Holy Land, visiting Amman, Bethlehem and Jerusalem between May 24 and 26.

He said he would hold an "ecumenical meeting with all the representatives of the Christian Churches in Jerusalem" at the Church of the Holy Sepulchre in east Jerusalem, built on the sites where Jesus is believed to have been crucified, buried and resurrected.

Pope Francis was invited to visit the Holy Land by Israeli President Shimon Peres and Palestinian president Mahmud Abbas.

The 77-year-old pontiff has made many appeals for peace in the Middle East.

During his meeting with Mr Abbas, he called for a "just and lasting solution" to the conflict between Israelis and Palestinians.