WASHINGTON - The internal watchdog at the US Justice Department said on Wednesday he is launching a review into allegations by Republican lawmakers that the FBI made serious missteps when it sought a warrant to monitor a former adviser to President Donald Trump's 2016 election campaign.Michael Horowitz, the department's inspector general, said in a statement his review will examine whether the Federal Bureau of Investigation and the Justice Department followed proper procedures when they applied for a warrant with the Foreign Intelligence Surveillance Court to secretly conduct surveillance on Carter Page and his ties to Russia.Attorney General Jeff Sessions told reporters last month he planned to ask Horowitz to investigate the alleged surveillance abuses.The allegations were outlined in a memo commissioned by US House Intelligence Committee Chairman Devin Nunes and declassified for public release by Trump, over the objections of Justice Department officials and Democrats on the panel.The Republican memo claims that the FBI used in part a dossier compiled by former British intelligence officer Christopher Steele to justify the warrant, and failed to disclose to the court that Steele was employed by a firm funded by Democrats to do opposition research on Trump's business dealings.The FBI staunchly opposed the public release of the memo at the time, saying there were "material omissions of fact."Democrats on the House Intelligence Committee have since released their own memo, accusing Republicans of deliberately omitting facts in an effort to undermine Special Counsel Robert Mueller's investigation into whether Trump's campaign colluded with Russia.The Democrats concluded that the Justice Department did not engage in misconduct when applying for the warrant.House Judiciary Committee Ranking Democrat Jerrold Nadler said it is a "shame" that Horowitz must devote resources to probe a "conspiracy theory."Trump lambasted Sessions in late February for referring the Republican memo to Horowitz for investigation. The president wrote in a tweet: “Why is A.G. Sessions asking the Inspector General to investigate massive FISA abuse? Will take forever, has no prosecutorial power and already late with reports on Comey, etc.”Trump's tweet mischaracterized the role inspector generals play in investigating alleged misconduct inside federal agencies, and it prompted Sessions to issue a sharp rebuttal defending his decision.Horowitz was sworn into his post in 2012 during the Obama administration, and previously served on the U.S. Sentencing Commission under Republican President George W. Bush.A still non-public report by Horowitz accusing former FBI Deputy Director Andrew McCabe of lack of candor was used recently as the basis for Sessions to fire McCabe on March 16, less than two days before he was set to retire.Despite Trump's prior concerns with letting Horowitz investigate the alleged surveillance abuses outlined by Republicans, the president cheered the decision to terminate McCabe, calling it on Twitter a "great day for Democracy."