Prime Minister Najib Abdul Razak is slated to meet United States President Donald Trump in Washington next month.

The White House stated that the meeting, which comes following US secretary of state Rex Tillerson's visit to Kuala Lumpur earlier this month, is scheduled for Sept 12.

The Najib-Trump meeting also follows the US Department of Justice (DOJ) hitting the pause button on its 1MDB-related civil forfeiture suits to facilitate ongoing criminal investigations into the matter.

This ignited speculation that Najib had managed to strike a deal with the Trump administration.

Commenting on the forthcoming meeting in Washington, Dr Mahathir Mohamad said Trump could endorse Najib if he wanted to.

"If Trump wants to participate in our election, he can give his endorsement to the man the US Department of Justice described as a thief and kleptocrat," Mahathir said in Putrajaya this morning.

The former prime minister was speaking to reporters in Putrajaya after attending the Royal Commission of Inquiry (RCI) hearing on the foreign exchange (forex) losses incurred by Bank Negara as an observer.

The DOJ suits had implicated businessman Jho Low, who is said to be close to Najib's family, and the prime minister's stepson Riza Aziz.

The suits also mentioned Malaysian Official 1 (MO1), the person who Minister in the Prime Minister's Department Abdul Rahman Dahlan confirmed to be Najib.

However, Rahman said, since the prime minister was not named, the latter was not being investigated.

In its latest filing on June 15, the DOJ alleged that Low had purchased a 22-carat pink diamond pendant and necklace, valued at US$27.3 million, for the wife of MO1.

Najib has denied abusing public funds for personal gain and blamed such allegations on those conspiring with Mahathir to topple him from power.

Following investigations carried out by various agencies, attorney-general Mohamed Apandi Ali claimed that there were no grounds to file charges against Najib.

After last year's US presidential election, a spokesperson for Najib's office told the British broadcaster BBC that Trump was the prime minister's “golfing buddy”.

Th spokesperson also revealed that the US president had inscribed a photograph of the pair as "To my favourite PM".

Najib also acknowledged that he had a personal relationship with Trump, saying that the latter was not a stranger to him.

Whereas Najib's wife, Rosmah Mansor, recalled how her husband and Trump spoke on the phone in the wee hours of the morning, and how Najib had scolded her when she woke him up.

Meanwhile, news of Najib's meeting with Trump comes amid claims that China President Xi Jinping would be visiting Malaysia at the end of the year.

Since the US commenced its probe into 1MDB, Najib has been seen as gravitating towards China.