Saudi Arabia has presented Lebanon and Syria with a proposed agreement to defuse tensions, amid rising Arab alarm over the steady deterioration in relations between the two countries since last February’s killing of Rafiq Hariri, the former Lebanese prime minister.

Prince Saud al-Feisal, Saudi Arabia’s foreign minister, said in an interview with the Financial Times on Monday that the kingdom had found a set of general principles for an agreement, but was waiting for a response from Beirut and Damascus, where details would have to be worked out.

“Now it’s in the hands of both countries and they will let us know,” he said.

Prince Saud made clear the kingdom was not seeking a compromise on the UN probe into the Hariri assassination – an investigation that is continuing but which has already implicated high-level Syrian officials in the murder.

“This [initiative] has nothing to do with the investigation. We are as anxious as anyone to find out who the perpetrators are and we want them to be found quickly,” he said.

Without directly commenting on UN demands to interview Bashar al-Assad, the Syrian president, Prince Saud said Saudi Arabia had urged Syria to co-operate with the UN probe “without reservations”.

Arab press reports have cited a seven-point plan, worked out by Saudi Arabia and Egypt, that includes putting an end to media campaigns, ceasing provocative statements from politicians, exchanging diplomatic representation and co-ordinating foreign policy.

In Beirut, anti-Syrian politicians have already said such a proposal would be tantamount to reviving Syrian dominance over Lebanon. However, Prince Saud said the principles were designed to pave the way for negotiations between Beirut and Damascus on details of an agreement.

The murder of Mr Hariri, a popular Lebanese leader and close Saudi ally, provoked the departure of Syrian troops from Lebanon in April and led to unprecedented international pressure on Damascus. Syria denies responsibility for the killing.

But with the UN investigation uncovering alleged high-level Syrian links and Lebanese politicians accusing Damascus of involvement in several subsequent assassinations of anti-Syrian figures, tensions between Beirut and Damascus have escalated.

Syria’s allies in Lebanon have suspended their participation in government, creating a domestic political crisis.

The media war between Beirut and Damascus has intensified and some Lebanese politicians have openly called for the ouster of the Syrian regime.

In Damascus, the Assad regime has been rattled by the recent defection of Abdelhalim Khaddam, a former vice-president. In media interviews, Mr Khaddam has directly blamed Mr Assad for the Hariri killing, sparking new concerns over the future of the regime.

Prince Saud said the priority for Saudi Arabia was to reduce tensions between Lebanon and Syria and prevent more chaos in the region.

“We have enough problems as it is,” he said. “It’s about time we resolve the ones we have – Palestine, Iraq – instead of establish more.”