Afghanistan's minister for mines, Mir Muhammad Sadiq, made the comment on Tuesday after attending a meeting in Islamabad to review the 1680km Afghan-Turkmen pipeline project.
The project has been on hold from the 1990s when the Taliban came to power. Since US-led forces ousted their government in late 2001, the $3.5 billion project has been revived and has gained Washington's support.
The pipeline would tap into natural gas wells at Turkmenistan's huge Dauletabad-Donmez field, which holds more than 100 trillion cubic feet in gas reserves.
''We are fully capable of protecting the Afghan-Turkmen gas pipeline,'' Mir Muhammad Sadiq said in Islamabad after a meeting with the ministers from Turkmenistan and Pakistan.
Pakistani Minister for Petroleum Aman Allah Jadun said he was satisfied with Afghanistan's assurances.
''We are fully capable of protecting the Afghan-Turkmen gas pipeline''
Mir Muhammad Sadiq,
Afghan Minister for Mines
He added that Islamabad had no reservations about India joining the project. He said ministers from the three countries would meet again on Wednesday.
"We have given some figures to Turkmenistan about our gas demands; but we will send them a detailed report about it soon. We hope, they will get back to us within a month," Jadun said.