WASHINGTON - Malaysian Prime Minister Najib Razak and US President Donald Trump appeared to hit it off at the White House on Tuesday afternoon (Sept 12) as they talked about trade and the fight against the Islamic State in Iraq and Syria (ISIS).

"It's an honour to have you here," Mr Trump told Datuk Seri Najib in front of reporters at the start of their delegation-level meeting.

Hours after their meetings, Mr Najib tweeted, "Thank you President @realDonaldTrump for the warm welcome & hospitality afforded to me and members of my delegation. Much was discussed, from bilateral trade to combating extremism. I look forward to stronger ties between our two nations."

Mr Trump also tweeted: "It was a great honor to welcome Prime Minister Najib Abdul Razak of Malaysia and his distinguished delegation to the @WhiteHouse today!"

It was the first visit of a Malaysian Prime Minister to the White House since 2004. But the two leaders were no strangers, having played golf together at Mr Trump's course in Bedminster - where the real estate tycoon reportedly gave Mr Najib a picture of the two together on which he wrote: "To my favorite prime minister."

"We're talking about trade - very large trade deals," Mr Trump said before the media left the room. "We're working on one deal where between US$10 billion and US$20 billion worth of Boeing jets are going to be purchased, General Electric engines will be purchased, and many other things."

"Also, Malaysia is a massive investor in the United States in the form of stocks and bonds, and the stock exchange."

On the security relationship - a critical aspect of their relationship - Mr Trump said: "The Prime Minister has a major role in not allowing (the Islamic State)… and others to exist.

"He's been very, very strong on terrorism in Malaysia, and a great supporter from that standpoint. So that's a very important thing to the United States," Mr Trump said.

"He does not do business with North Korea any longer, and we find that to be very important," he added.

Mr Najib opened the conversation with three "strong value" propositions.

"Number one, we want to help you in terms of strengthening the US economy," he said.

"We intend to increase the number of Boeing planes to be purchased by MAS (Malaysian Airlines). We are committed to 25 planes of the 737 MAX 10, plus eight 787 Dreamliners. And there is a strong probability - not possibility - that we will add 25 more 737 MAX 10 in the near future.

"So within five years, the deal will be worth beyond US$10 billion (S$13 billion). That's one. We will also try to persuade AirAsia to purchase GE engines," he said.

Mr Najib said Malaysia's Employees Provident Fund, which already had close to US$7 billion in equities in the US, would invest an additional US$3-US$4 billion to support infrastructure development - a cornerstone of the Trump agenda. The sovereign fund Khazanah also planned to increase its investment in high tech companies, he added.

On the security front, Mr Najib told Mr Trump: "We are committed to fight Daesh, ISIS, Al-Qaeda, Abu Sayyaf - you name it. They are the enemy of the United States, they are also the enemy of Malaysia, and we will do our part to make sure that our part of the world is safe.

"The key to it is to support moderate and progressive Muslim regimes and governments around the world, because that is the true face of Islam; that is the authentic face of Islam," he emphasised. "The more you align with progressive and moderate regimes, the better it would be in terms of winning the hearts and minds of the Muslim world."

They were the right messages for Mr Trump, analysts said. Asked later if the ongoing Department of Justice (DOJ) investigation into kleptocracy at Malaysia's state investor 1MDB figured in the discussion between the two leaders, White House press secretary Sarah Huckabee Sanders said she was not aware that it had.

Mr Najib and his wife are staying at the Trump International Hotel. Asked if that was appropriate, Ms Sanders shot back: "We certainly don't book their hotel accommodations, so I couldn't speak to the personal decision they made about where to stay here in DC."

Dr Zachary Abuza, professor at the National War College in Washington told The Straits Times. said: "Both Trump and Najib are highly transactional figures."

Mr Najib was "clearly looking for international recognition and approval ahead of the upcoming elections" and wanted to deflect focus from the DOJ investigation, he said.

"Trump is seeking Malaysian cooperation on North Korea and the Islamic State," Dr Abuza said. "While only a small part of its overall trade portfolio, the DPRK is so isolated that even relatively small partners can be important for their importation of otherwise banned materials and help to launder and mask other trade.

"Malaysia is an important partner in that it is serious about the threat posed by ISIS, and far more proactive about it than it was with the rise of Jemaah Islamiyah" the professor said.

"It's security forces are competent and well resourced, though increasingly politicised. Malaysia is very different from the Philippines which is a black hole for aid and assistance, and whose situation continues to devolve."

But he cautioned: "That said, Malaysia is not the partner that they claim to be. Many of their policies, such as crackdowns on Shia, Ahmadis or policies towards ethnic and religious minorities, have made Malaysia a much less tolerant and secular society."

Later at a dinner with the US-Asean Business Council and US Chamber of Commerce on Tuesday, Mr Najib said there was a campaign to deliberately sabotage state investor 1Malaysia Development Berhad (1MDB) to undermine investor confidence in Malaysia's economy, according to Malaysian media.

He said the move was a failed attempt to topple the government, The Star Online reported.

"I know that some of you will have heard some less positive stories about the Malaysian economy, particularly about 1MDB. Rather than brush the issue under the rug, we ordered investigations into the company at a scale unprecedented in our nation's history,'' the report said.

"And, when it became clear that there had been failings, I instructed that the company be rationalised. This process is progressing well and many of the assets formerly owned by 1MDB are thriving," Mr Najib was quoted as saying.

On Wednesday US time, Mr Najib will speak at a closed-door session at the Centre for Strategic and International Studies, and meet lawmakers in the Capitol.