Gordon Brown paved the way today for the announcement next Tuesday of a large US troop surge in Afghanistan by saying he had received assurances from NATO countries that they would contribute an extra 5,000 troops.
The assurances are significant because both Brown and Barack Obama have said they will not commit more of their own troops unless there are increases in other NATO troop numbers.
There was some confusion in NATO circles as to the source of Brown's optimism that the number of troops could rise by 5,000, but the prime minister's spokesman said his assessment came after discussions with 10 coalition partners.
In his letter to the NATO secretary general, Anders Fogh Rasmussen, the prime minister said he was optimistic that "a majority of these countries will indeed make available increased numbers of troops, and more police trainers and civilian support".
He said the troop numbers would be in addition to his own offer of nearly 500 more troops. Brown did not name the countries, the number of troops or the mix between troops trained to fight and forces deployed to train the Afghan army.
Brown said: "In addition to offering security, the troops must train and mentor the Afghan armed forces and police so that, over time, they can take responsibility for the security of their country."
He also firmed up his plans for a conference on Afghanistan in January in the UK jointly with the UN. He has spoken of the possibility of a conference before, but his remarks suggest it will now go ahead.
He said one aim of the conference would be to decide "when we move forward with district by district handover to Afghan control. Recent announcements by President Karzai of action against corruption are an essential part of this process."
Brown is hoping the London conference will give him the opportunity to set a date by which British troops could be expected to leave Afghanistan so the issue can be defused before the general election. He is also hoping that Karzai has started to do more to prove he will deal with corruption in the next few years, including by allowing prosecutions to go ahead against specific former ministers.
The prime minister's spokesman said Brown intended to make a commitment to root out corruption in the Kabul administration one of the main issues of the conference. It will also look at how to strengthen provincial power and break the cycle of poor co-ordination on aid and governance.
Mullah Omar, the Taliban leader in Afghanistan, has ruled out talks with Karzai and called on Afghans to break off relations with his "stooge" administration. In a statement, he also insisted foreign troops were losing the war in Afghanistan.