Russian President Vladimir Putin hosted U.S. business leaders at his opulent summer residence Saturday in an effort to reassure them that his government remains committed to free-market principles and welcomes foreign investment. Putin told the executives from companies that included Citigroup, Intel and IBM that he hoped U.S.-Russian economic ties would continue to grow. "In the next three to four years, we can go to a higher level, we have all the preconditions for this," Putin said at the start of the meeting at the 18th century Konstantin Palace outside St. Petersburg, Russia's one-time imperial capital. He promised that his government would work to streamline tax regulations and set clear rules for foreigners' involvement in Russia's strategic energy sector and other key areas of national economy.