Turkey’s president says Istanbul’s airports and the Saudi consulate are being monitored following the disappearance of Saudi writer Jamal Khashoggi, and he is still hopeful Khashoggi is alive.

Recep Tayyip Erdogan made the comments to journalists in Ankara, Turkey, on Sunday, calling Khashoggi a “journalist and a friend”.

“God willing we will not be faced with the situation we do not desire,” he said.

Erdogan said he was personally following the case and would announce the results of an investigation at an undisclosed time.

Reports published on Saturday by various international media, citing Turkish officials, alleged that Khashoggi was killed at the Saudi consulate in Istanbul.

Saudi officials have called the allegation “baseless”.

A friend of Khashoggi’s said Turkish officials told him to “make your funeral preparations” as Khashoggi had been killed at the consulate.

Turan Kislakci, who is the head of the Turkish-Arab Media Association, told the Associated Press he was advised that there was evidence Khashoggi was killed in a barbaric way.

Kislakci said he was told Khashoggi was made to “faint”, then was dismembered.

Khashoggi is a columnist for the Washington Post, and its editorial page editor Fred Hiatt said if the reports of murder are true it is a “monstrous and unfathomable act”.

“Jamal was – or, as we hope, is – a committed, courageous journalist,” Hiatt said in a statement.

“He writes out of a sense of love for his country and deep faith in human dignity and freedom.”

Khashoggi, who has lived in self-imposed exile in Washington for the past year fearing retribution for his criticism of Saudi policies, entered the consulate on Tuesday to secure documents for his forthcoming marriage, according to his fiancee, who waited outside. He has not been heard from since.

According to two sources quoted by The Washington Post, the journalist died earlier this week at the hands of a Saudi assassination squad.

A statement released on Sunday by the state-run Saudi Press Agency SPA cited a diplomatic officer who categorically denied “these baseless allegations, and expressed his doubt that they came from Turkish officials that are informed of the investigation or are authorised to comment on the issue”.