US diplomats offered Ukraine a meeting with Trump in exchange for political investigation The FEC chairman warned against accepting quid pro quo tied to an election.

Two top U.S. diplomats promised Ukraine’s government a meeting with President Donald Trump if its president agreed to launch an investigation that would have involved Trump’s political rival, former Vice President Joe Biden, and his son, according to newly released texts.

The bombshell texts were expected to fuel the ongoing impeachment inquiry by House Democrats, and put increasing pressure on Republicans to defend the administration’s actions.

In text messages provided to the House Intelligence Committee, Kurt Volker – at the time the special envoy to Ukraine – tells a top aide to Ukraine’s President Volodymyr Zelenskiy that Zelenskiy would have to persuade Trump in a phone call later that day – July 25 -- that he’s willing to initiate an investigation.

Volker was pressing Ukraine to announce it would examine potential 2016 election meddling, an apparent reference to conservatives’ claims that Ukrainian politicians had tried to help Hillary Clinton beat Trump. Volker also wanted Ukraine to say it would look into the dealings of Burisma, an energy company that employed Biden’s son, Hunter, on its board.

In one July exchange, he writes to the Ukrainian government aide that Zelenskiy will be granted a meeting in Washington – if he meets U.S. conditions.

“Heard from White House — Assuming President Z convinces trump he will investigate / ‘get to the bottom of what happened’ in 2016, we will nail down date for visit to Washington.”

The aide later responded that the phone call between the two leaders went well. More than a week later, on Aug. 10, the aide says the Ukrainian president is willing to make the statement on the investigation the U.S. wants, but requests a date for the meeting first.

By September, after it became clear that hundreds of millions of dollars in U.S. aid to Ukraine may have been on the line too, a third career foreign service officer weighed in declaring such a quid pro quo would be “crazy.”

The head of the Federal Election Commission on Friday retweeted her past statement that any quid pro quo intended to benefit a political campaign violates election laws.

“It is illegal for any person to solicit, accept, or receive anything of value from a foreign national in connection with a U.S. election,” she wrote.

Three House Democrats chairing key oversight committees said in a statement that the texts show a pattern of abuse of power and that they were particularly alarmed by Trump publicly calling for China to also investigate the Bidens.

“It is unethical, unpatriotic, and wrong,” the Democrats wrote. “American Presidents should never press foreign powers to target their domestic political rivals.”

Republicans mostly defended the president or remained silent on the matter, although Texas Republican Rep. Will Hurd, who announced this summer he is retiring his House seat, said he was disturbed by the texts.

“I think some of these things are indeed damning,” he told CNN on Friday. “However I want to make sure we get through this entire investigation before coming to some kind of conclusions.”

Trump, who on Thursday openly said not only Ukraine but China should investigate the Bidens, insisted in tweets Friday that he did nothing wrong asking – that it was about ending corruption not politics.

“As President I have an obligation to end CORRUPTION, even if that means requesting the help of a foreign country or countries,” he tweeted. “It is done all the time. This has NOTHING to do with politics or a political campaign against the Bidens. This does have to do with their corruption!”

ABC News' Conor Finnegan and Katherine Faulders contributed to this report.