Washington, Aug 28 (IANS): US President Donald Trump offered brief praised for the late Republican Senator John McCain, who passed away on August 25, in a statement after responding only with silence to questions about the Vietnam War veteran turned politician.

"Despite our differences on policy and politics, I respect Senator John McCain's service to our country," Trump wrote in the four-paragraph statement on Monday, which dealt mainly in the logistical details he had approved for the week-long remembrance ceremonies.

Later, while meeting Evangelical leaders in the State Dining Room, Trump told reporters: "Our hearts and prayers are going to the family of Senator John McCain... And we very much appreciate everything Sen. McCain has done for our country," CNN reported.

After facing criticism for raising the flags at the White House to full-staff after lowering them on Saturday, Trump said he had approved them to be lowered again.

It is a customary tradition in the US that after the death of a person such as McCain - a Vietnam War veteran and prisoner of war who was tortured during his captivity, ultimately served for decades in the Senate and was the Republican presidential nominee in 2008 - for flags to be lowered to half-staff until after the funeral.

He also wrote that he asked Vice President Mike Pence to deliver remarks at a ceremony celebrating McCain's life in the US Capitol on Friday.

Asked what had changed and why the proclamation was issued on Monday, press secretary Sarah Sanders would only say this was the "President's decision to do and the statement speaks for itself".

Monday's statement came after Trump maintained his silence during a string of appearances in front of the media, choosing to ignore questions about the late Arizona Republican.

On Sunday when he was questioned whether he believed McCain -- a former Navy pilot who was shot down over Vietnam -- was a hero, Trump remained stone-faced behind the Resolute Desk in the Oval Office after announcing a trade breakthrough with Mexico.

The President had openly feuded with McCain, even as the Senator was dying from brain cancer.

McCain is scheduled to be buried on September 2, at the Naval Academy in Annapolis, Maryland, after a funeral service is held at the National Cathedral in Washington on Saturday.