Pakistan has urged Iran to respect its borders.
Pakistan's Foreign Ministry made the statement on February 18, one day after Tehran said it might send forces into Pakistan to free kidnapped border guards if Islamabad did not take measures to secure their release.
The guards were reportedly seized on February 6 in Iran's Sistan-Baluchistan Province.
Jaish-ul Adl, a little-known Sunni Islamist militant group, claimed responsibility for the kidnapping.
"Pakistan has already informed the Iranian authorities that its Frontier Corps teams have intensively combed the entire region but could not verify the entry or presence of the abducted Iranian border guards on its territory," said the statement by Pakistan's Foreign Ministry.
It added that it was possible the kidnappers, along with the abducted guards, were still hiding within the Iranian territory.