Jaap de Hoop Scheffer, Nato`s secretary-general, has warned Vladimir Putin that next week`s summit of the 26-member Atlantic alliance must not be marred by a new display of "unhelpful rhetoric" from Russia`s president, directed at the west, according to Financial Times.

As the military alliance`s national leaders prepare to meet in Bucharest for the annual gathering, tensions between Nato and Russia are running high because of Washington`s insistence that Ukraine and Georgia should be allowed to take a significant new step towards joining the organisation.

But while the secretary-general said he was looking forward to frank exchanges between Mr Putin and alliance leaders at a session of the Nato-Russia Council, he said he hoped the discussion would also be constructive.

"The volume of music we get next week will to a large extent depend on the tone that President Putin uses in the NRC," Mr de Hoop Scheffer told the Financial Times in an interview. "I do not know what that tone will be."

However, the secretary-general expressed the hope that Mr Putin, who will be attending a Nato summit for the first time, would not use the occasion to launch another blunt threat to the west.

Mr de Hoop Scheffer said: "Let`s try to avoid unhelpful rhetoric, like, `We will target missiles on nation A, B and C.` That is not only unhelpful. It makes me remember a time when I grew up when there was a Berlin Wall and Iron Curtain. . . So let us refrain from rhetoric."

Next week`s summit could mark a significant development in relations between Nato and Russia. Although Mr Putin will be in Bucharest, the recent election of Dmitry Medvedev as his successor has raised hopes in many European states that relations between Moscow and the west may be on the mend.

Mr de Hoop Scheffer said there were positive signs this was happening. In recent days, he remarked, there had been "hopeful, positive results" from US-Russia talks on Washington`s plans to deploy a missile defence shield in eastern Europe - a move bitterly opposed by Moscow.

However, President George W. Bush`s insistence that Ukraine and Georgia should be offered a chance to join Nato`s Membership Action Plan - a major milestone on the road to full membership - has left some uncertainty about how the Bucharest meeting will go.

Mr de Hoop Scheffer said he was not surprised at how hard the US was pressing for Georgia and Ukraine to join the MAP. "I know President Bush well, and I know he is committed to giving as many nations as possible the right to enjoy what he and I consider basic human values and to defend those values."

However, he acknowledged that it was far from clear whether the US could persuade Nato members such as Germany that an offer of the MAP to the two former Soviet republics would not be a slap in the face for Mr Medvedev.

"This is what the allies are going to discuss next week," he said. "What the outcome will be cannot yet be predicted."

The good news for Mr de Hoop Scheffer is that on the biggest issue on the Nato agenda - its 47,000 ISAF troop deployment in Afghanistan - next week should see some big improvement.

Recent months have seen serious squabbling among alliance members on burden-sharing for the ISAF force. But Mr de Hoop Scheffer told the FT that the "pieces are coming together". He was confident the alliance would receive fresh contributions from President Nicolas Sarkozy of France, in what would be one of the highlights of the Bucharest meeting.

He also said that Canada, which threatened to pull out of Afghanistan if it failed to get sufficient back-up from other countries, "will get the support they have asked for". On Afghanistan, there would also be a strong focus on spelling out out a "comprehensive approach" to the international community`s operations.

The secretary-general`s message was that while Nato`s primary role was to ensure security, it was operating "under Afghan ownership". Other organisations, meanwhile, such as the United Nations and World Bank, had a big role to play in bolstering the economy and helping the fight against the narcotics trade.

"Nato is an important player," he said, "but it is not the only player. Nato does not want to co-ordinate others, but to co-ordinate with others."

As a result, next week`s summit will be attended by leaders from a wide range of bodies, including President Hamid Karzai of Afghanistan, Ban Ki- moon, the UN secretary-general, and José Manuel Barroso, the European Commission president.

Scheffer CV

* Appointed Nato secretary-general in 2004

* Former leader of the Dutch Christian Democratic Alliance

* From 1986 to 1994, was a member of the Parliamentary Assemblies of the Council of Europe and the Western European Union

* In 1990, during the first Gulf war, served as WEU rapporteur on the consequences of the invasion of Kuwait and continuing operations in the Gulf region

* Chairman of the Organisation for Security and Co-operation in Europe when the Netherlands held the chairmanship in 2003

* As secretary-general of Nato, he has spoken out about the danger of splits between alliance members, particularly regarding policy in Afghanistan.

By James Blitz in Brussels, The Financial Times