BEIJING (Reuters) -A group of U.S. lawmakers on a rare visit to Beijing raised a deal with top Chinese leaders which would see China commit to buy more Boeing jets, Adam Smith, a U.S. Democratic Representative, told a press conference on Tuesday. U.S. Ambassador to China David Purdue said he thought the negotiations had entered their last days or weeks, adding that the deal is "very important to the president." Boeing is in talks to sell as many as 500 jets to China, Bloomberg reported last month.