ANKARA, Feb. 2 (Xinhua) -- Turkey's constitutional change bill was submitted to President Recep Tayyip Erdogan for approval on Thursday, state-run Anadolu Agency reported.

According to the law, Turkish President will have 15 days to approve or reject the bill, which will shift Turkey to an executive presidential system from the current parliamentary system.

If approved, it will be published in the country's Official Gazette, setting the date for a vote.

The Turkish parliament approved the constitutional amendments on January 21 as deputies completed two rounds of voting on 18 articles.

A total of 339 MPs voted in favor of the package which will be put to vote in a national referendum that will likely be held in early April.

The referendum date will be selected by the Supreme Election Board after President Erdogan approves the amendments.

The national referendum is expected to be held on either April 9 or April 16, said Anadolu Agency.

On Dec. 30, the ruling Justice and Development Party and the opposition Nationalist Movement Party submitted the constitutional amendments to parliament for ratification.