The White House is seen in Washington D.C., the United States, on Dec. 18, 2019. U.S. Democrat-led House of Representatives is engaging in a heated, polarized floor debate that will last for several hours on articles of impeachment ahead of historic impeachment votes over President Donald Trump on Wednesday. (Photo: Xinhua)

The US House of Representatives will vote on Wednesday to send articles of impeachment against President Donald Trump to the Senate, the Wall Street Journal and other US media have reported.

Reports say the Senate impeachment trial procedure could begin as early as this week.

On December 18, the House voted to approve two articles of impeachment against Mr Trump, making him the third US president to be formally impeached by Congress after former presidents Andrew Johnson and Bill Clinton. The articles of impeachment proposed by Congressional Democrats against Trump include abuse of power and obstruction of Congress.

Democrats believe Trump used a White House meeting and military aid to pressure Ukraine to investigate allegations of corruption in Ukraine by the son of Trump's domestic political rival, former vice-president Joe Biden. Democrats have also accused Trump of obstructing cooperation by administration officials while Congress investigated the matter.

House Speaker Nancy Pelosi did not immediately send the articles of impeachment to the Senate after they were passed. For more than three weeks, Pelosi has held up the articles in the House, citing the need to know how the Senate would proceed.

Pelosi's move is believed to be an effort to pressure Senate Republicans to agree to hear more witnesses at the start of the Senate trial, among other demands. John Bolton, a former national security adviser who was personally involved in the Trump administration's diplomacy with Ukraine, recently said he would testify if subpoenaed, further complicating the partisan game.

So far, the Senate Republican leadership has not made clear whether it will call new witnesses to testify.

There are some divisions within the Republican party between centrists and Trump's political allies. The former do not want to appear too protective of Trump, especially those such as Maine Senator Susan Collins, who face 2020 election races. On the contrary, Republicans such as Missouri Senator Josh Hawley, a staunch supporter of Trump, have argued that if the Senate calls new witnesses at the trial, Joe and Hunter Biden should also be included.

The US constitution does not specify how the Senate will handle impeachment cases. Historically, the chief justice of the Supreme Court will preside over the trial. In the trial itself, a panel of lawmakers from the House will play the role of prosecutor, the president will have a team of defense lawyers, and the Senate will serve as a jury.

If, in the end, more than two-thirds of the Senators approve of the articles of impeachment, the incumbent president is removed and the vice-president takes over. Currently, Republicans hold the majority in the Senate, and no Republican Senator supports removing Trump.