Nato's secretary general is visiting Israel to discuss improving military co-operation between the two sides.
Mr De Hoop Scheffer has ruled out Nato membership for Israel
But Jaap de Hoop Scheffer ruled out the possibility of Israel becoming a Nato member in the foreseeable future.
Israel has shown an interest in joining the 26-member alliance, but Mr de Hoop Scheffer made it clear Arab countries would be hostile to the idea.
He said Nato would consider sending peacekeeping troops if a Middle East peace treaty was signed.
Mr de Hoop Scheffer's visit is seen as a public endorsement of the increasingly close relationship between Nato and Israel.
The two have held joint military exercises and are keen to improve co-operation in areas such as the sharing of intelligence and combating the proliferation of weapons of mass destruction.
Mr de Hoop Scheffer is holding talks with Israeli Prime Minister Ariel Sharon and Foreign Minister Silvan Shalom.
But in an interview with Israel's Haaretz newspaper, he said his talks with Israel and other Middle East countries had to be carefully balanced "given the sensitivities in the region".
He said such talks were not "a first step to a future membership" with Nato.
But he stressed that the alliance did want "an increased political and practical relation" with Israel.
Mr de Hoop Scheffer said Nato would not get involved in the peace process.
"But I believe that should one day the two parties in conflict come to an agreement, and should they request some sort of Nato assistance... then Nato would certainly need to discuss such a request".
He said any deployment would require a United Nations mandate.