Trump says meeting Pope Francis was "an honor"

Last year, the Pope had reprimanded Trump over his proposal to build a wall along the US-Mexico border. The pontiff had said a person who thinks of building walls and not bridges is "not Christian."

Trump had responded saying it was "disgraceful" of Pope Francis to question his faith.

Trump's disregard of environmental issues are at odds with Francis's efforts to counter climate change.

The Vatican had taken a dim view of Trump's anti-Muslim rhetoric.

Pope Francis has championed the cause of refugees, including those from Syria, while Trump has shut the US' borders to all Muslim refugees.

The Vatican had also expressed concern over the Trump administration's executive orders banning travellers from seven predominantly-Muslim countries from entering the US.

US President Donald Trump met Pope Francis during his visit to the Vatican.

Trump was heard saying it was "an honor" for him to meet the Pope, as the two shook hands and sat down for a private half-hour discussion.

The seemingly warm meeting is a departure from the previous sharp exchanges between both men, who share opposing views on climate change and immigration.

During the meeting, Trump was accompanied by First Lady Melania, daughter Ivanka, her husband Jared Kushner, Secretary of State Rex Tillerson and National Security Adviser HR McMaster.

Pope Francis shook Melania's hand and jokingly asked her in Spanish: "what do you feed him?"

Melania supposedly answered "Pizza," but a recording of the exchange wasn't clear.

Trump and the Pope then exchanged gifts.

Pope Francis was seen keeping a stern face while Trump beamed as both posed for photographs before their private conversation.

After their talk, a smiling and visibly more relaxed pontiff gave Trump a small sculptured olive tree and said it symbolizes peace.

"It is my desire that you become an olive tree to construct peace," Francis said.

Trump replied: "we can use peace."

Pope Francis gave Trump a signed copy of his World Peace Day message and three of his major writings, including a papal letter pushing for environmental protection.

"Well, I'll be reading them," Trump promised and went on to give the pontiff a boxed set of Martin Luther King's writings.

While he was leaving, Trump told Pope Francis, "I won't forget what you said."

Trump's Vatican visit could be an attempt at uniting the world's three biggest religions against Islamic terrorism. Before coming to the Vatican, Trump visited Saudi Arabia and Israel.

"We thought that this trip was essential to put together the Muslim faith, the Jewish faith and… the Christian faith" in a coalition against terrorism, a White House official said.