LONDON, Sept 6 (Reuters) - Britain's new prime minister, Liz Truss, has named James Cleverly as her foreign minister, her office said in a statement on Tuesday.

Cleverly had served as Education Secretary since July, when Boris Johnson announced he would resign and appointed a caretaker government until a new leader was appointed.

Cleverly, 53, has risen rapidly through the Conservative ranks since he was first elected as the member of parliament for the English town of Braintree in 2015.

He has also served in the foreign ministry as a junior minister, often giving parliamentary updates on Britain's support for Ukraine following Russia's invasion.

As foreign secretary, Truss established herself as a critic of China as well as Russia, and Cleverly has indicated that her government will take a tough line with both Moscow and Beijing.

"We absolutely have to stand firm in our support to President (Volodymyr) Zelenskiy and the people of Ukraine, we absolutely have to do that. And I have no doubt we will continue to be as firm friends now as we have been under Boris Johnson," Cleverly told Reuters on Monday shortly after Truss was announced as the new Conservative leader.

"But of course, that's not the only issue. It's the most pressing, the most immediate, but it's not the only issue. We have to deal with that but we also have to deal with longer term issues as well. And ... we will do both."

Like Truss, Cleverly stayed loyal to Johnson and he was an early backer of Truss' campaign to replace him as leader.

Cleverly made his own pitch to be leader in 2019, when former prime minister Theresa May stepped down, but was the first candidate to drop out of the race.