US President Barack Obama called Tuesday for more transparency and rule of law if the United States and Russia are to boost economic ties."We need to make it easier for US companies to invest in Russia, and Russian companies to invest in the US," he told a US-Russia business summit in Moscow, where he appeared jointly with Russian President Dmitry Medvedev. "We have to promote transparency, accountability and the rule of law."Obama was concluding a two-day trip to Russia, during which he and Medvedev pledged to negotiate a new arms treaty that would reduce both countries' nuclear arsenals by about one-third.But the relationship between the former Cold War adversaries has to be about more than disarmament, Obama said. "It has to be about our common prosperity, the jobs we create, the innovation we unleash," he said. "America seeks a prosperous Russia."Obama said trade between the two countries amounts to only $36 billion a year, or 1 percent of the United States' global trade volumes, which he pointedly said put Russia on par with Thailand.Foreign businesses have identified corruption and a weak judiciary as among the main stumbling blocks to boosting investment in Russia.Russian business leaders seemed cheered by Obama's efforts to "reset" the relationship - a term coined by the US administration.Viktor Vekselberg, a billionaire shareholder of Anglo-Russian joint venture TNK-BP, said better relations with the US were essential for Russian business, given current tensions with the European Union. Russia has sparred with the EU over energy and has resisted Europe's efforts to improve economic and political ties with former Soviet bloc states through the Eastern Partnership agreement."With the US, it's simpler and more important," Vekselberg said. "Obama has demonstrated he really wants to reshape this relationship."