MH17 dad's emotional letter read to Pompeo

US secretary of state Mike Pompeo has been read an emotional letter from an Australian father who lost three children when MH17 was shot down four years ago.

Mike Pompeo says the US is taking the loss of MH17 seriously after being read an emotional letter. (AAP)

US Secretary of State Mike Pompeo says America will continue to hold Russia accountable for the 298 people, including 38 Australians, killed when Malaysia Airlines Flight 17 was shot down over Ukraine by a Russian missile four years ago.

Pompeo was told of the ongoing pain families of victims, including Perth parents Anthony Maslin and Rin Norris who lost their three children Otis, Evie and Mo and their grandfather Nick Norris in the incident.

A letter from Maslin was read by a reporter to Pompeo at a press conference on Tuesday in California at the conclusion of the annual Australia-US Ministerial (AUSMIN) talks.

"We need the Russians to continue to be held accountable for that," Mr Pompeo responded.

"We take this matter seriously."

Pompeo, US Secretary of Defense James Mattis and Australian Foreign Affairs Minister Julie Bishop and Defence Minister Marise Payne spent the past two days at the AUSMIN talks, held at Stanford University.