Defense Minister Avigdor Liberman
Defense Minister Avigdor LibermanMarc Israel Sellem/Fash90

US Defense Secretary Ashton Carter on Monday met Israeli Defense Minister Avigdor Liberman for the first time, the Pentagon said, offering few details about the visit.

"They have had a good conversation," said a senior US defense official with knowledge of the meeting.

It was Liberman's first foreign visit since being sworn in on May 30.

It comes with the United States and Israel in the process of negotiating a new 10-year defense aid pact to replace the current one, which expires in 2018 and grants the Jewish state more than $3 billion per year

Following Liberman's nomination, US State Department spokesman Mark Toner, in a rare comment on Israeli internal politics, said the Jewish state's new ruling coalition raised "legitimate questions" over Israel's commitment to a two-state solution in its conflict with the Palestinians, due to the new defense minister's sometimes hardline comments.

But Netanyahu and Liberman both have sought to allay concerns over the appointment, saying they are committed to the two-state solution.

On Wednesday, Liberman is due to attend a ceremony in Dallas marking the development of US defense firm Lockheed Martin's F-35 fighter jet, which Israel is purchasing, and tour a factory of Israeli weapons manufacturer Elbit Systems.

Israel has so far ordered a total of 33 F-35s and will be the only country in the Middle East to have the jet, which the US military is just beginning to use after years of delays and technical problems.

A Pentagon statement said Carter and Liberman had "reaffirmed the strength of the US-Israeli defense relationship and the United States' unwavering commitment to Israel's security."

The pair discussed "regional security challenges in the Middle East and areas of mutual defense cooperation," the Pentagon said.