WASHINGTON - Three senior Democratic senators, in a rare show of bipartisanship, urged US President Donald Trump to stand up to China as he weighs launching an investigation of its intellectual property and trade practices.Senate Democratic leader Chuck Schumer encouraged the Republican president to skip the investigation and go straight to action against China."We should certainly go after them," said Schumer in a statement. Senators Ron Wyden of Oregon and Sherrod Brown of Ohio also urged Trump to rein in China.Trump has frequently attacked China over steel imports and technology and pressured Beijing to do more to rein in North Korea's missile program.Trump is considering encouraging US Trade Representative Robert Lighthizer to launch an investigation of China under the 1974 Trade Act's Section 301 and could make an announcement within days, a senior administration official said.The act allows the president to unilaterally impose tariffs or other trade restrictions to protect US industries.The United States has a long list of grievances with China, ranging from accusations of steel dumping to theft of US companies' intellectual property.China counters that trade between the two nations benefits both sides, and that Beijing is willing to improve trade ties.North Korea is a point of major friction for Trump and China, with the president saying China needs to do more to restrain Pyongyang's nuclear and missile programs. Beijing has said its influence on North Korea is limited.A senior Chinese official said on Monday there was no link between North Korea's nuclear program and China-US trade.Wyden, the top Democrat on the Senate Finance Committee, wrote to Lighthizer urging action to stop China from pressuring US tech companies into giving up intellectual property rights.Wyden's state of Oregon is home to several companies that could make a case regarding intellectual property rights and China, including Nike Inc and FLIR Systems Inc. His state is also home to Schnitzer Steel Industries Inc , which has accused the Chinese of dumping steel in the United States at a low price to drive down prices.Section 301 was often used in the 1980s against Japanese imports of motorcycles, steel and other goods. The law has seldom been used since the World Trade Organization formed in 1995 to resolve trade disputes.Lighthizer and Trump's Commerce Secretary Wilbur Ross have complained the WTO is slow and biased against the United States.Trump on April 20 launched a trade probe against China and other foreign exporters of cheap steel into the US market, citing national security concerns and raising the possibility of new tariffs.He announced the inquiry surrounded by US steel executives from Nucor Corp, United States Steel Corp and TimkenSteel Corp.