(Provided by Reuters)

WASHINGTON — Speaker Nancy Pelosi sharpened the focus of Democrats’ impeachment case against President Trump on Thursday, accusing the president of committing bribery when he withheld vital military assistance from Ukraine at the same time he was seeking its commitment to publicly investigate his political rivals.

The speaker’s explicit allegation of bribery, a misdeed identified in the Constitution as an impeachable offense, was significant. Even as Ms. Pelosi said that no final decision had been made on whether to impeach Mr. Trump, it suggested that Democrats are increasingly working to put a name to the president’s alleged wrongdoing, and moving toward a more specific set of charges that could be codified in articles of impeachment in the coming weeks.

© Erin Schaff/The New York Times Speaker Nancy Pelosi during her news conference on Thursday in the Capitol. “The devastating testimony corroborated evidence of bribery uncovered in the inquiry, and that the president abused his power and violated his oath by threatening to withhold military aid and a White House meeting in exchange for an investigation into his political rival — a clear attempt by the president to give himself an advantage in the 2020 election,” Ms. Pelosi told reporters at her weekly news conference in the Capitol.

Democrats have begun using the term “bribery” more freely in recent days to describe what a string of diplomats and career Trump administration officials have said was a highly unusual and inappropriate effort by Mr. Trump and a small group around him to extract a public promise from Ukraine to investigate former Vice President Joseph R. Biden Jr. and a discredited theory about Democrats conspiring with Ukraine to interfere in the 2016 election.

The House Intelligence Committee convened the House’s first public impeachment hearing in two decades on Wednesday with testimony from William B. Taylor Jr., the top American diplomat in Ukraine, and George P. Kent, a senior State Department official responsible for policy toward the country.

© Erin Schaff/The New York Times Representative Kevin McCarthy, Republican of California, told reporters that the hearing had only confirmed that testimony about Mr. Trump was not first-hand and therefore could not be trusted.

They told the committee that Mr. Trump and his allies inside and outside of the government placed the president’s political objectives at the center of American policy toward Ukraine, using both $391 million in security assistance that Congress had appropriated for Ukraine’s war with Russia as well as a White House meeting that was coveted by the country’s new leader as leverage.

Asked to clarify her remarks later, Ms. Pelosi said: “The bribe is to grant or withhold military assistance in return for a public statement of a fake investigation into the elections. That’s bribery.”

She added: “We have not even made a decision to impeach, that is what the inquiry is about.”

Also watch: Dueling narratives emerge after new Ukraine revelations (Provided by Reuters)

Ms. Pelosi said Mr. Trump should give Congress exculpatory evidence, if he has it, and said the president would be given an opportunity to defend himself. Republicans and the White House have accused Democrats of denying Mr. Trump a proper say in the proceedings.

Ms. Pelosi’s remarks on impeachment were the first time she discussed the growing inquiry at length with reporters since Congress recessed in late October. She provided other clues as to how she is thinking about the case.

Asked if Democrats were successfully bringing the public along with them, Ms. Pelosi conceded that the country was likely too polarized to ever support impeachment as overwhelmingly as it did when Richard M. Nixon resigned the presidency in 1974. Public opinion polls now suggest a majority of Americans favor the impeachment inquiry, but only by a thin margin.

“Impeaching is a divisive thing in our country — it’s hard,” Ms. Pelosi said. “The place that our country is now, it’s not a time where you’ll go to 70 percent when President Nixon walked out of the White House.”

Indeed, there was no sign from congressional Republicans that the testimony had shaken their conviction that Mr. Trump is innocent.

Also watch: Political expert says 'Democrats overestimated interest' in impeaching Trump (Provided by AFP)

Representative Kevin McCarthy, Republican of California and the minority leader, told reporters that the hearing had only confirmed that the accounts from Mr. Taylor, Mr. Kent and other witnesses who have offered damaging information about Mr. Trump are not firsthand, and therefore could not be trusted. And he pointed back to a July phone call between Mr. Trump and President Volodymyr Zelensky of Ukraine at the heart of the impeachment inquiry.

“The call summary is still the most important piece of evidence we have, and it shows no pressure or even mention of conditionality between the two leaders,” Mr. McCarthy said.

The White House released a reconstructed transcript of the call in September that showed that after the Ukrainian leader thanked Mr. Trump for military assistance, the American president pivoted and asked Mr. Zelensky “to do us a favor, though.” Mr. Trump then asked Mr. Zelensky to investigate unsubstantiated corruption accusations against Mr. Biden and his son Hunter who worked for a Ukrainian energy firm, as well as a conspiracy theory that Ukraine, not Russia, interfered with the 2016 election to help Democrats.

The United States intelligence community has concluded that Russia interfered to help Mr. Trump.