Nato said it would resume contacts with Russia after its April summit
Nato has agreed to resume high-level contacts with Russia, working with what US Secretary of State Hillary Clinton called a "greater unity of purpose".
Russia welcomed the move, six months after Nato froze contacts over the conflict between Russia and Georgia.
Mrs Clinton stressed Afghanistan, which she called "Nato's biggest military challenge", was a mutual concern.
She has raised the idea of a conference on the issue, with the participation of "all stakeholders", including Iran.
"If we move forward with such a meeting, it is expected that Iran would be invited as a neighbour of Afghanistan," she said.
French Foreign Minister Bernard Kouchner said that he hoped Iran would attend such a meeting, but noted that Tehran had failed to attend recent French talks on Afghanistan.
"I hope Iran will be here this time," said Mr Kouchner.
"We can and must find ways to work constructively with Russia where we share areas of common interest, including helping the people of Afghanistan," said Mrs Clinton.
Nato remains the central pillar of the trans-Atlantic relationship but it is facing a critical military and political challenge in Afghanistan, where failure could call into question its whole credibility, BBC diplomatic correspondent Jonathan Marcus reports from Brussels.
US foreign policy is now very much a team game and US Vice-President Joe Biden will be in Brussels next Tuesday for a more detailed exchange of views on Afghanistan, our correspondent adds.
"We are resuming the talks within the Nato-Russia Council as soon as possible after the summit," in early April to mark the 60th anniversary of Nato, said Slovak Foreign Minister Miroslav Lajcak.
A statement from the Russian foreign ministry said: "This decision is a step in the right direction."
"It's time to explore a fresh start," Mrs Clinton said.
On Friday, she will hold talks with Russian Foreign Minister Sergei Lavrov.
But UK Foreign Secretary David Miliband told the BBC that it was not "business as usual" with Moscow.
Mr Miliband said the resumption of ties would provide an opportunity to engage with Moscow "in a hardheaded way".
He said "the invasion of Georgia and continuing infringement of its sovereignty" could not be "swept under the carpet".
Mrs Clinton added that Nato "should continue to open Nato's door to European countries such as Georgia and Ukraine and help them meet Nato standards".
Earlier, Russia's envoy to Nato defended the war against Georgia and said any new relationship with Nato would be on Moscow's own terms.
Earlier, Nato Secretary General Jaap de Hoop Scheffer said that areas of common interest included Afghanistan, counter-terrorism and non-proliferation.
Some, like Germany and France, had long been pressing for the resumption of ties with Russia, arguing that their suspension has been counter-productive.
Dmitry Rogozin, Russia's permanent envoy to Nato, predicted an outcome of the Brussels talks "that should, on the whole, satisfy Russia" but made clear he saw Moscow negotiating from a position of strength.
Scheffer welcomed Mrs Clinton to her first Nato meeting
"We came out of the crisis that we had after the August 2008 events [the war with Georgia], the crisis in the South Caucasus, stronger," he told Russian channel Vesti TV.
"Our Western colleagues saw in Russia a partner that one cannot wipe one's feet on. We are strong... and we are restoring cooperation, including on our terms."
Nato will, nonetheless, be trying to show that more normal business with Russia does not mean that the alliance is abandoning countries like Georgia and Ukraine, our correspondent says. Their foreign ministers came to Brussels too.