Iran and the US share an interest in a stable Afghanistan
Iran has agreed to attend a US-backed international conference on Afghanistan next week, but Washington played down the prospect of a high-profile meeting.
While US Secretary of State Hillary Clinton is also due to attend, the state department said she had no plans for a "substantive" meeting with Iran.
Iran's foreign ministry said it had not yet decided whom it would send to the one-day conference at The Hague.
Both countries have an interest in a stable Afghanistan.
"We will participate in the Afghanistan meeting," said Iranian foreign ministry spokesman Hassan Ghashghavi Ghashghavi.
"At what level, I don't know yet, but we will participate."
US state department spokesman Gordon Duguid said there were no plans for a substantive meeting "at this time".
America, he added, hoped the Iranians would play a "positive" role in trying to stabilise Afghanistan.
UN Secretary General Ban Ki-moon as well as delegates from more than 80 countries are due to attend next Tuesday's meeting.
During her visit to Europe earlier this month, Mrs Clinton proposed the summit and said Iran should be a part of it.
"There are a lot of reasons why Iran would be interested so they will be invited," she said at the time.
"Obviously it is up to them to decide whether to come."
Confirmation of Iran's attendance is likely to be welcomed by Washington, which has not had diplomatic ties with Tehran for three decades.
Tensions have been high over Iran's nuclear work, which Washington says is aimed at building an atomic bomb and Tehran insists is a civilian energy programme.
President Barack Obama has said the US is ready to talk to Iran if it "unclenched its fist".
Details of a review of US strategy on Afghanistan, which is battling a growing Taleban insurgency, are expected to be released ahead of the conference.
Iran, which opposed the Taleban regime toppled by the US-led invasion in 2001, has experienced a rise in drug use as easily available heroin from Afghanistan flows across the border.