Prime Minister Binali Yıldırım accepted main opposition Republican People's Party (CHP) chairman Kılıçdaroğlu's invitation to drink tea together as he arrived at the parliament to vote for the new constitution proposal late Tuesday.

Kılıçdaroğlu reportedly saw Yıldırım passing by the opposition chamber as he headed to the General Assembly and invited him over to his room to chat and drink tea together.

The unplanned meeting struck the media's attention, as the two leaders have differing views on constitutional change and the presidential system.

Yıldırım and his assistants accepted Kılıçdaroğlu's invitation and discussed current issues with the opposition. The two sides reportedly joked around, and enjoyed each other's company, despite a tense atmosphere that surrounded the parliament during debates on constitutional reform.Parliament's General Assembly launched talks on Monday on the long-debated constitutional amendment package, after 338 out of 550 deputies voted in support of the planned package and adopted the first two articles of the bill. Proposed by the ruling Justice and Development Party (AK Party) and backed by the Nationalist Movement Party (MHP), the constitutional amendment foreseeing Turkey's transition to a presidential system was discussed at the Parliament's General Assembly on Monday.

The AK Party expects the whole process to be concluded within 17 days and publish the amendment in the official gazette by the end of January, after being ratified by the president. In the case that the amendment is published in the official gazette on Jan. 31, Turkey will go to the referendum in April to vote for the amendment.