Former US president Barack Obama greets Donald Trump at his inauguration as president. January 20, 2017.
Former US president Barack Obama greets Donald Trump at his inauguration as president. January 20, 2017.

US President Donald Trump on Saturday accused his predecessor Barack Obama of "wiretapping" his phone just before last year's presidential elections.

Trump made the claim on Twitter, failing to mention whether the information was part of a briefing or in the public domain.

However, one tweet was not enough. Trump followed with a volley of messages, 140 characters long or less.

The matter escalated quickly as Trump called Obama a "bad or sick man":

Trump also took the opportunity to publicly defend US Attorney General Jeff Sessions. Sessions is under fire from the public, Republicans and Democrats for being in contact with the Russian ambassador to the US twice during Trump's election campaign.

A report carried by the Washington Post revealed Sessions had met Russian Ambassador Sergei Kislyak twice. However, at his confirmation hearing last month, he denied any contact with Russian officials during the election campaign, the report added.

Trump in another tweet said Sessions' first meeting with the Russian Ambassador was arranged by the Obama Administration. He went on to say this:

Trump's administration has come under pressure from FBI and congressional investigations into links between some of his aides and campaign staff, and Russian officials before he was elected president. Trump's former national security adviser, Michael Flynn, resigned in February after revelations that he had discussed US sanctions on Russia with Kislyak before Trump took office.

Trump has often used his Twitter account to attack rivals and for years led a campaign alleging that Obama was not born in the US. He later retracted the allegation.

Source: TRTWorld and agencies