Turkish President Recep Tayyip Erdogan spoke by phone on Monday with Greek Prime Minister Kyriakos Mitsotakis to extend his best wishes for the latter’s 56th birthday.

Late last month, the Greek leader was one of many world leaders who wished Erdogan a happy 70th birthday on Feb. 28.

This unexpected gesture of goodwill between the leaderships of the two Aegean neighbors and NATO allies, who have been historical rivals on several issues, marks a rare recent moment of cordiality. However, tensions between Athens and Ankara have thawed recently, as the two leaders moved towards a normalization over the past year, punctuated by Erdogan’s significant visit to Athens in December.

The two leaders have already arranged a face-to-face meeting in Turkey for this spring, likely scheduled between May 5 and May 15.

Another round of high-level talks between respective defense ministry delegations of the two countries will precede the May meeting, and specifically on confidence-building measures (CBMs). These talks are again expected to avoid touching on major long-standing “differences”, instead confirming a more positive climate in bilateral relations, and focusing on so-called “low-impact” issues.