"Kulbhushan is not eligible for consular access nor will be granted consular access", said Pakistan Armed Forces spokesperson Major General Asif Ghafoor.
Early this week, Pakistan had rejected India's assertion that it is violating a bilateral pact by not giving access to retired Indian Navy officer Kulbhushan Jadhav, who has been sentenced to death by a military court there.
Apart from the letter, India's High Commissioner to Pakistan Gautam Bambawale also conveyed to Pakistan Foreign Secretary Tehmina Janjua, the request for consular access for Mr. Jadhav, for the 16th time. The Pakistan Army has also released a confessional video of Jadhav after his arrest.
Pakistan on Wednesday informed India that the consular access agreement between the two countries was for prisoners and did not include spies.More news: Investors are Watching Shares of NVIDIA Corporation (NASDAQ:NVDA)
A Pakistani military court this month ordered the punishment for Jadhav, after he was accused of espionage and sabotage activities in Karachi and Balochistan.
This is the second time the Indian High Commissioner has called on Janjua since the death sentence was handed to Jadhav on April 10.
Pakistan has claimed that Mr Jadhav, 46, was arrested from the restive Balochistan province on March 3, 2016, where he was working as a spy for intel agency Research and Analysis Wing or RAW.
The formal appeal against the death sentence, filed under Section 133 (B) of the Pakistan Army Act, was signed by Jadhav's mother. "They have applied for necessary visas with the Pakistan High Commission in New Delhi", Baglay added.More news: Turkey arrests 1000 in connection with 2016 failed coup
Mr. Jadhav's case was also discussed by Foreign Secretary S. Jaishankar and Pakistan High Commissioner Abdul Basit in a meeting held on Tuesday, the MEA said.
But, India has denied Pakistan's allegation that Jadhav was a spy and alleged that he was kidnapped by the Pakistan authorities. Bambawale repeated India's demand for consular access during the meeting.
The Pakistan Foreign Office said due judicial process was followed during Jadhav's trial and that he was provided with a lawyer in accordance with the Constitution of Pakistan. The Pakistani army claimed that Jadhav is a serving officer in the Indian Navy.More news: Customers have mixed emotions about McDonalds new employee uniforms