Washington (CNN) After devastating testimony from one of his own ambassadors, Secretary of State Mike Pompeo is now ensnared at the center of the impeachment probe he has denounced as "Washington noise."

Gordon Sondland, who was appointed by President Donald Trump to be US ambassador to the European Union, testified Wednesday that he had kept Pompeo "in the loop" about "activities" connected to the effort to get Ukraine to announce an investigation into Trump's main political rival.

Sondland's testimony directly tied Pompeo to the pressure campaign being carried out in Ukraine -- a campaign to which the secretary of state has largely avoided being publicly tied.

The revelations come at a sensitive time for Pompeo amid speculation he may be eyeing a run for the Senate from Kansas next year.

In a damning opening statement, Sondland testified that he had told Pompeo and other senior officials at the State Department and other government agencies about his pursuits in Ukraine and his dealings with the President's personal lawyer, Rudy Giuliani. Sondland said they had been specifically apprised of efforts to get Ukrainian President Volodymyr Zelensky to publicly announce investigations into Burisma -- a Ukrainian natural gas company that had hired Joe Biden's son Hunter -- and the 2016 election.

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