VOA correspondent Henry Ridgwell contributed to this report from Kyiv.
WHITE HOUSE - U.S. President Donald Trump is maintaining his phone call with Ukraine's president that has initiated an impeachment inquiry was innocuous.
After President Volodymyr Zelenskiy earlier in the day stated there was "no blackmail" in the July 25 call with Trump, the U.S. leader told reporters, "We released a perfect conversation. The president of Ukraine just confirmed that and that should be case over."
It is far from case over in the House, controlled by the opposition Democrats, where the impeachment inquiry is gaining steam.
House committees on Thursday issued a subpoena for Trump's energy secretary, Rick Perry, as well as two associates of the president's outside lawyer, former New York City Mayor Rudy Giuliani.
"I don't know why they would be calling Rick Perry. I don't know why they would be calling all these people. It is a very bad situation for our country," Trump said to reporters on the White House South Lawn before boarding the Marine One helicopter.
House Democrats say Perry may have "reinforced the stark message" Trump conveyed to Zelenskiy. Perry says his only interest was to get Trump to talk to the Ukrainians on energy matters.
According to a whistleblower complaint, and a rough transcript of the call released by the White House, Trump urged Zelenskiy to open an investigation into former Vice President Joe Biden, a leading contender for next year's Democratic Party nomination to face Trump in the general election.
The White House is refusing to participate in the impeachment inquiry, calling it "unconstitutional."
The three main House committees conducting the impeachment inquiry have released a set of text messages obtained from former U.S. envoy to Ukraine Kurt Volker, including one Volker sent to Zelenskiy aide Andrey Yermak saying, "We will nail down date for visit to Washington" if Zelenskiy "convinces Trump he will investigate."
Zelenskiy was elected in April on a platform of rooting out corruption. Now the Ukrainian leader is facing criticism over his own conduct, according to political analyst Ilya Kusa of the Ukrainian Institute of the Future.
"It has become his first international diplomatic crisis. He allowed us to get involved in the American elections and this is not the thing that we should have done because we have plenty of our own problems and trying to get into this process it's too global, too big a game to play. And, of course, too risky because Ukraine here is just a gambling chip," says Kusa.
Trump has accused Biden of corruption, alleging that when he was vice president, he threatened to withhold loan guarantees to Ukraine unless the government stops investigating a gas company for which Biden's son, Hunter, held a seat.
There is no evidence of any wrongdoing by Joe or Hunter Biden.
Volker last week gave closed-door testimony to the House Intelligence, Foreign Affairs and Oversight committees.
The State Department has blocked U.S. Ambassador to the European Union and Trump donor Gordon Sondland from giving voluntary testimony. It is uncertain if the committees will be able to go ahead with their scheduled Friday meeting with former Ambassador to Ukraine Marie Yovanovitch.