WASHINGTON • Democrats in the US House of Representatives who are pursuing an impeachment inquiry against President Donald Trump have issued a subpoena to Secretary of State Mike Pompeo for documents concerning contact with Ukraine's government.

Following a whistle-blower complaint that Republican President Donald Trump had solicited a political favour from Ukraine's President that could help him get re-elected, the lawmakers are pursuing concerns that Mr Trump's actions have jeopardised national security and the integrity of US elections.

The House Foreign Affairs, Intelligence and Oversight Committees which announced the subpoena on Friday have also scheduled depositions for five State Department officials over the next two weeks.

The five include former US envoy to Ukraine Marie Yovanovitch; Mr Kurt Volker, the US Special Representative for Ukraine, who has just resigned; and Ambassador to the European Union Gordon Sondland.

The committees announced the subpoenas after the Trump administration missed a Thursday deadline to provide documents and information about contacts with Ukrainian officials, as well as a July 25 telephone call between Mr Trump and Ukrainian President Volodymyr Zelenskiy.

That telephone call is central to an impeachment investigation that Ms Nancy Pelosi, the Speaker of the Democratic-led House of Representatives, announced this past week.

The impeachment inquiry has cast a new pall over Mr Trump's presidency just months after he emerged from the shadow cast by special counsel Robert Mueller's investigation into whether he colluded with Russia in the 2016 election.

Mr Trump has reacted furiously, arguing that he did nothing wrong, and accusing Democrats of launching a politically motivated "witch hunt".

More than 300 former national security officials from both Republican and Democratic administrations on Friday endorsed the House's impeachment inquiry, saying they did not prejudge the outcome but wanted to know more facts.

REUTERS