US President Donald Trump on Wednesday said he encouraged India and Pakistan to work out their differences in separate meetings with their prime ministers this week.

"I said, 'Fellas, work it out. Just work it out'," Trump told a news conference after attending the United Nations General Assembly.

"Those are two nuclear countries. They've gotta work it out," he said.

Tensions between India and Pakistan reached a feverish pitch on August 5, when New Delhi unilaterally annexed occupied Kashmir, revoking a constitutional guarantee that gave a special status to the disputed territory. A strict lockdown and communications blackout was imposed in the region that has snapped off ordinary people's internet and mobile telephone service across much of occupied Kashmir. The clampdown has continued for over 50 days.

Addressing a joint press conference alongside Prime Minister Imran Khan ahead of their meeting, Trump on Monday repeated his earlier offer to mediate between Pakistan and India on the Kashmir issue. Trump first offered to mediate during a meeting with Prime Minister Imran in July.

"If I can help, I will certainly do that," he said. "If both (Pakistan and India) want, I am ready, willing and able to do it," the US president said on Monday.

Without specifying, Trump said he had heard a "very aggressive" statement from Indian Prime Minister Narendra on Sunday, adding: "I hope they (Pakistan and India) are going to be able to come together and do something that's really smart and good for both.

"There is always a solution and I do believe that there is a solution," he added.

The meeting between Trump and Imran on Monday followed a "Howdy, Modi!" rally in Houston over the weekend in which the US president and Modi shared a stage and showered each other with praise.

Addressing a press conference on Tuesday along with Modi, in response to questions from Indian journalists, Trump once again reiterated his offer of arbitration to reduce tensions between India and Pakistan, despite New Delhi’s repeated rejection of his offers.

Read: Trump evades Pakistan-bashing trap

Asked "How do you make sure that you clamp down on terrorism from Pakistan?" the US leader said: "Well, I had a very good meeting with Prime Minister [Imran] Khan. It was a long meeting and we discussed a lot."

He then made his first — and the third this week — reference of the day to his mediation offer.

"And I think he’d like to see something happen that would be very fruitful, very peaceful. And I think that will happen, ultimately. I really believe that these two great gentlemen (Prime Minister Imran and Prime Minister Modi) will get together and work something," he said.