After a four-hour discussion with German Chancellor Helmut Kohl, President Yeltsin said many of the obstacles in the way of closer ties had been removed. "A treaty will be signed on 27 May between Russia and Nato," he said.
His statement was in sharp contrast to official Russian utterances in the last few days, which had held the partnership treaty hostage to the ongoing row about Nato expansion.
Russia and Nato are due to sign an agreement in Paris next month, formalising Moscow's new friendly role in European security.
Officials accompanying Mr Yeltsin to Germany had hinted at last-minute difficulties. "If the treaty is not binding and concrete on military matters, then there would scarcely be any point for Russia to sign such a document," declared Sergei Yastrzhembsky, the President's spokesman, on the eve of the meeting with Mr Kohl.
After yesterday's encounter, however, it was all sweetness and light.
Mr Kohl said that "Ninety per cent of questions" had been settled, and he was convinced the remaining 10 per cent would be cleared up by the time of the Paris summit. Although the Chancellor did not elaborate on the 10 per cent, Mr Yeltsin said he was categorically opposed to Nato weaponry, whether it was nuclear or conventional, spilling over into the former Soviet block countries which are about to be co-opted into Nato.
If there is no linkage between Russia's treaty with Nato and the problems vexing Nato expansion, then the West has two more months to find a solution which will accommodate Moscow.
At the end of July the Alliance is expected to issue formal invitations to Poland, the Czech Republic and Hungary. Only one of these, Poland, borders on Russian territory, but Moscow is not prepared to tolerate any new member so close to its frontiers becoming a major Nato arsenal, let alone a nuclear base.
How Nato satisfies these objections without appearing to cave in to Russian pressure is largely up to the deft handling of the German Chancellor, who appears to enjoy the full confidence of his Russian counterpart.
Mr Yeltsin was fulsome in praise for "my friend Helmut" and the support he had provided in the Nato negotiations, prompting the Chancellor at one point to draw attention to Germany's full commitment to Nato. He promised to help his Kremlin friend, but said he would not play the role of interpreter.
The meeting in Baden-Baden, a town full of well-heeled pensioners recovering from debilitating illnesses, was the fifth between the two men in just over a year. When Mr Yeltsin fell ill, the Chancellor sent a doctor to Moscow.
Yesterday, the Russian President repaid the compliment by presenting his German chum with the captured personal archives of Walther Rathenau, the German foreign minister who signed the peace of Rapallo with Russia.
Mr Yeltsin was invited to Germany to receive the "Man of the Year" prize, awarded to him by the German media last year. He could not receive it as scheduled last November because of his heart surgery. A German human rights group, the Society for Threatened Peoples, said the heavy casualties in the Chechnya war and the death under fire of journalists there, meant it was a "mockery" to give Mr Yeltsin the prize.