Ehud Barak
Ehud BarakFlash 90

In a reminder that Turkey and Israel are still in a diplomatic row, Turkish president Abdullah Gul refused to attend a formal lunch in Vienna on Friday after being informed that the event was attended by Israeli Defense Minister Ehud Barak.

Gul chose not to participate in the lunch and instead visited a residential neighborhood of Turkish immigrants in the Austrian capital.

Both men were in town for the two-day World Policy Conference, AFP reported.

The deterioration in the relationship between the two countries began when Turkey demanded that Israel apologize for the deaths of nine Turkish nationals onboard the Mavi Marmara in May of 2010. The Turkish citizens were killed when Israeli soldiers who boarded the Gaza-bound ship were forced to open fire after being attacked by the activists on board with clubs and knives.

Prime Minister Binyamin Netanyahu refused to apologize for the incident, and Turkey responded by downgrading its diplomatic ties with Israel.

Turkish Prime Minister Recep Tayyip Erdogan further deteriorated the tense situation when he chose to verbally attack Israel on several occasions.

In one instance, Erdogan threatened to dispatch Turkish warships to escort aid ships from his country to Hamas-ruled Gaza.

Israel’s Foreign and Defense Ministries have chosen not to comment on Friday's incident in Austria.