The Afghan President Hamid Karzai has accepted the need for a second round in the nation's presidential election, following widespread fraud in the first.
The run-off is scheduled to take place on 7 November when Mr Karzai will face the former foreign minister, Abdullah Abdullah.
Political leaders from around the world have been reacting to the news:
BAN KI-MOON, UN SECRETARY GENERAL
I commend President Karzai for the leadership he has displayed and for his commitment to ensuring full respect for Afghanistan's constitution and its democratic processes.
You can understand there is a huge challenge in conducting a second election.
We will try to ensure that all Afghan people should be able to express their own will freely without intimidation or threat.
We will do our best... to make these elections fair and free of fraud.
BARACK OBAMA, US PRESIDENT
President Karzai's constructive actions established an important precedent for Afghanistan's new democracy.
The Afghan constitution and laws are strengthened by President Karzai's decision, which is in the best interests of the Afghan people.
It is now vital that all elements of Afghan society continue to come together to advance democracy, peace and justice.
We look forward to a second round of voting, and the completion of the process to choose the president of Afghanistan.
GORDON BROWN, BRITISH PRIME MINISTER
It's absolutely vital that Afghanistan has a legitimate government, one that has the support of the people, clearly seen to have the support of the people.
And therefore this announcement today - that has been made in a statesmanlike way by President Karzai - is absolutely vital to the future of Afghanistan.
There had been doubts about a number of the votes, there has been fraud in the election, there have been questions asked about the legitimacy of some of the processes.
It is right that these are dealt with in a way that leads to confidence that Afghans' insipient democracy, its democracy can be strengthened for the future.
NICOLAS SARKOZY, FRENCH PRESIDENT
President Karzai's statement shows to all that he is a statesman who can decide on what is essential, in the higher interests of his country and of the unity of the Afghan people...
After long weeks of examining the results, these were announced at the end of a process that does honour to Afghanistan.
France will remain by the side of the Afghan people and its future government.
JAVIER SOLANA, EU HIGH REPRESENTATIVE FOR FOREIGN POLICY
I welcome the announcement... today and the statement of President Karzai accepting a second round of elections.
I urge all parties with a stake in the elections to do their utmost to ensure that the turnout of the second round provides for a credible and secure process.
It should lead to a credible and legitimate result.
JOHN KERRY, CHAIR OF THE US SENATE FOREIGN RELATIONS COMMITTE
There has been no clear resolution to the election. Leaving many Afghans with legitimate concerns and fears about the future.
President Karzai himself had serious questions about the process but today he showed statesmanship by deciding to move forward and to strengthen the country by embracing the constitution and the rule of law.
A time of enormous uncertainty has been transformed into a time of great opportunity.
The international community is committed to carry out this election... and to make the runoff a success.
We know it will be difficult and require sacrifice. But we are committed to this effort.