"I want to thank you very much for all of the investments you made in the United States," Trump said. He lauded stock market growth under his presidency, noting Malaysia's vested interests in American financial markets.

"We are very proud of our stock market and what's happened since I became president," Trump said. "I congratulate you on those investments."

North Korea on agenda

He also sought to flatter his new US counterpart -- including by staying in Trump's Washington hotel during his stay.

"We come here with a strong value and proposition to put on the table," Najib said in the Cabinet Room, listing the new airplane and equipment investments as examples of cooperation between the two countries.

Beforehand, the White House said the meeting would focus primarily on security issues and North Korea, and not the corruption scandal. Trump has been seeking partners in Asia to help counter Pyongyang amid new provocations.

Malaysia's relations with North Korea have deteriorated since February, when Kim Jong-Un's half-brother was assassinated with a nerve agent at the Kuala Lumpur airport. The attack was widely believed to have been carried out by agents of North Korea.

Since then, Malaysia has cut off some ties to Pyongyang, though Trump has hoped for greater cooperation from Asian allies in his bid to curb North Korea's nuclear ambitions.

Trump downplayed a new round of sanctions against North Korea approved by the United Nations Security Council on Monday, saying they were only a "small step."

"Those sanctions are nothing compared to what ultimately will have to happen," he said. The topic is expected to dominate next week's UN General Assembly meetings, which Trump indicated on Tuesday he was looking forward to attending.

Strategy in Asia

Trump is looking to bolster regional counters to China, particularly in Southeast Asia, where maritime disputes in the South China Sea and trade practices remain irritants to Washington-Beijing ties.

Malaysia is situated at an important shipping channel, the Straits of Malacca, making it an important ally to both China and the US. China is the largest foreign investor in Malaysia, and three Chinese companies are involved in a plan to build a new deep sea port in Malacca costing billions of dollars.

Malaysia, a majority Muslim nation, has also acted as an important US partner in countering Islamic terrorism in the region, which Trump praised Tuesday.

Trump has yet to visit Asia, but plans to attend conferences in Vietnam and the Philippines in November. He's expected to stop in additional Asian capitals during that trip.

White House press secretary Sarah Sanders said this week that the Justice Department investigations were not expected to arise when Trump meets Najib in the Oval Office.

"That investigation is apolitical and certainly independent of anything taking place tomorrow," she said on Monday.

Najib has met Trump before, and boasts of a warm relationship with the billionaire former businessman. The pair played a round of golf at Trump's Bedminster, New Jersey, golf club before Trump was president, and a photograph of the occasion hangs in the clubhouse there.

Then-President Barack Obama also once enjoyed Najib's company on the golf course. The two played golf during Obama's Christmastime vacation in Hawaii in 2014.

But the corruption allegations cooled relations between Malaysia and the United States in the final years of Obama's administration. The US also took issue with Malaysia's crackdown on media and free speech.

CNN's Ben Westcott contributed to this report.