Iran's foreign ministry says a U.S. security deal with Kabul is not "useful" for Afghanistan, and also impact "regional issues" negatively.
The Bilateral Security Agreement with the United States would keep thousands of troops in Afghanistan past a 2014 deadline. Iran is concerned about a U.S. military presence on its borders.
Afghanistan's President Hamid Karzai has endorsed but is delaying signing the agreement, even though a national assembly of Afghan dignitaries approved it last week.
Iranian ministry spokeswoman Marzieh Afkham said Tuesday that the "Islamic Republic of Iran does not consider the signing and approval of the pact useful for the long term expediencies and interests of Afghanistan''.