Putin acknowledged that the "resurrection of a strong, independent Russia" in his eight years in office had not made relations easy, but he said his successor Dmitry Medvedev had an opportunity to build ties.
A 90-minute meeting with US President George W. Bush and other NATO leaders in Bucharest yielded no big breakthroughs on disputes ranging from Kosovo to a planned US missile shield that have dragged ties to a post-Cold War low.
But although Putin reaffirmed Russia's fierce opposition to NATO's enlargement plans as a potential threat, his tone was very different from the searing attacks he has launched on Washington and its allies over the past year.
"Let's be friends, guys, and be frank and open," he told a news conference, declaring that another Cold War was impossible.
Putin's appearance marked the first time in six years that NATO leaders have invited the Russian leader to a summit and comes a month before he hands over to his protege Medvedev.
Today, Putin will host Bush -- also in the twilight of his presidency -- at his Black Sea villa in Sochi to explore US ideas for a possible strategic framework security pact which Bush would like to leave as a legacy.
"You know we're two old warhorses and we're both getting ready to step down from our positions," Bush told the NATO-Russia summit, according to a US official.
He said Bush also appreciated comments by Putin that Russia felt Washington was listening to its security concerns about a planned US missile shield.
Bush in turn acknowledged that "we have more work to do to convince the Russian people that NATO is not a threat, but a tool to deal with the challenges of the 21st century."
NATO Secretary-General Jaap de Hoop Scheffer told a news conference: "I cannot report that this morning we saw stunning breakthroughs." But he added: "The talks were in a positive spirit."
German Chancellor Angela Merkel called for more frequent meetings with the Russian leader and said: "NATO is not against anyone -- certainly not Russia. Russia is a partner."
Both Putin and Merkel said a solution ought to be possible on the stalled treaty curbing Conventional Forces in Europe. Moscow has suspended its participation, arguing the terms of the pact signed with the crumbling Soviet Union are unfair to it.
Few had dared predict the mood of the Putin encounter after NATO vowed that former Soviet Ukraine and Georgia would one day be members, without putting them on an immediate path to entry.
That compromise came on Thursday after Germany, France and smaller European states resisted US calls for the two to be granted Membership Action Plans (MAP), insisting they were not ready and pointing to risks of exacerbating tension with Russia.
Putin reiterated longstanding Russian concerns about NATO's intention to expand further eastwards and said Moscow would regard the emergence of a powerful military bloc on its Western borders as a "direct threat."
Summit generates 2,000 extra troops for Afghanistan
NATO leaders offered about 2,000 extra troops for the allied force in Afghanistan during the three day summit that ended Friday, officials said.
Georgia, a candidate for NATO membership, offered 500 troops and Poland confirmed it would send eight badly needed helicopters and 400 more soldiers. French President Nicolas Sarkozy said publicly on Thursday he would send 700 extra soldiers.
Poland and Georgia will split their new units between the southern and eastern regions -- the most dangerous parts of the country, said the officials who spoke on condition of anonymity since announcements of extra troops are usually left to national authorities.
Italy, Romania and Greece said they would add training teams for the Afghan army which are seen as key to NATO's strategic target of building up an effective Afghan force of 80,000 by 2010 which could eventually start to replace allied troops. NATO currently has around 30 such teams.
Other offers included 120 Czech special forces for the southern frontlines of the fight against the Taliban. Non-NATO member Azerbaijan said it would send 45 more soldiers and New Zealand said it would bolster its 120-strong contingent in Bamiyan province with 18 more troops.
Washington has lobbied for other nations to provide more troops for the 47,000 strong NATO force. Bucharest AP