MOSCOW: After two weeks recuperation from pneumonia, Boris Yeltsin was back in the Kremlin Wednesday, trying to prove once again he can perform as Russia's president. Yeltsin's press service said Yeltsin met with Prime Minister Viktor Chernomyrdin to discuss issues that have long awaited his return: back wages, tax collection and military reform. "He is returning to his working rhythm," chief Kremlin physician Sergei Mironov said Tuesday. "He gets tired somewhat more than before, but this is a natural reaction to the illness." On top of his weakness, Yeltsin faces more daunting political challenges than he did before. His foes in the lower house finally succeeded in putting a measure to oust the ailing president on the parliament's daily agenda, though it failed. But the political support for Yeltsin that previously stifled such attempts clearly is eroding; Yeltsin's visit to his office was apparently a timed effort to recoup some of that confidence. His doctors insist he has overcome the illness, and that he is sticking to plans for both a summit of former Soviet republics in Moscow next week and a February 4 trip to the Netherlands for talks with European leaders.