US President Barack Obama accused China of "gaming" international trade by keeping its currency weak, though he stopped short of backing a Senate bill aimed at pressing Beijing to revalue the renminbi, Reuters reported. "China has been very aggressive in gaming the trading system to its advantage and to the disadvantage of other countries, particularly the United States," Obama told a news conference on Thursday. The Senate bill, which would impose tariffs on Chinese goods if the renminbi does not appreciate further, faces opposition from House Speaker John Boehner, who argued that the move may trigger a trade war between the countries. Obama did not clarify whether he would veto the bill, but said he believed "a win-win trading relationship with China" was possible. Many observers say China deliberately undervalues its currency to give its export sector an advantage, while Beijing argues that it is committed to gradual reform and points out that the renminbi has appreciated roughly 30% against the US dollar since 2005.