Respected Liberal senator Arthur Sinodinos and Communications Minister Mitch Fifield will be recommended for two prestigious diplomatic posts as Prime Minister Scott Morrison reshapes his ministry.
Mr Morrison will recommend to the governor general that Senator Sinodinos replace Joe Hockey when he finishes his term as Australia's ambassador to the US, while Senator Fifield should fill the ambassador to the UN role.
"They will both be exceptional representatives and our countries interests abroad will be well served in that role," Mr Morrison said on Sunday.
Mr Morrison said both men had been offered cabinet roles, but decided on the diplomatic roles.
It had been rumoured that Senator Fifield was in line for a demotion from his communications portfolio, which will now be taken over by Paul Fletcher.
"It was Mitch's call about what he wanted to do; I would have been very happy for Mitch to continue to serve in communications and arts," Mr Morrison said.
Senator Sinodinos, who was on sick leave for some time for cancer treatment, said it was an opportunity for a more normal life.
"They have been through a lot in the last few years,' he said in a statement.
He said he would have big shoes to fill following former treasurer Mr Hockey into the job, but was looking forward to it.
"Australia and the United States are natural friends and allies. We share common strategic perspectives and a strong economic and trade relationship, well as cultural and historical ties."
Former prime minister Malcolm Turnbull tweeted his congratulations to Senator Sinodinos, a close friend.
"The role is more important than ever & Arthur will do an outstanding job - building on the great work of @JoeHockey our current Ambassador."
Mr Hockey's term is due to expire later this year and Senator Sinodinos will continue in the Senate for now.
Australian Associated Press