<span style="color: #222222;">US Secretary of State Mike Pompeo has said that his department will follow the law in the impeachment inquiry against President Donald Trump and defended his boss' attempts to push Ukraine to investigate former vice president Joe Biden.<br />'' <br />'' Pompeo's remarks came after the State Department missed a Friday deadline to comply with a subpoena issued by House Democrats to hand over documents related to the department's dealings with Ukraine and Trump attorney Rudy Giuliani.<br />'' <br />'' Democrats in the US House of Representatives are examining whether there are grounds to impeach Mr Trump, a Republican, based on a whistleblower's account that said he asked Ukrainian President Volodymyr Zelenskiy in a July 25 phone call to help investigate Democratic political rival Biden.<br />'' <br />''<br />''Mr Pompeo, who is travelling to Greece, told reporters that his department had sent a letter to Congress, which is their initial response to the document request. </span><br />