Pope Leo XIV appealed for “no more war” in a message to world powers during his first Sunday address at the Vatican.

Reflecting on current conflicts, the newly selected pontiff called for a “lasting peace” in the war in Ukraine, a ceasefire in Gaza, and welcomed Saturday’s agreement to end recent hostilities between India and Pakistan.

He said he was “deeply hurt” by events in Gaza, expressed hope for a “lasting accord” between India and Pakistan, and wished for a “authentic, true and lasting peace” in Ukraine.

The Pope also recited the Regina Caeli prayer, in honour of the Virgin Mary, to the crowd in St Peter’s Square.

Pope Leo was chosen as the new leader of the Catholic Church on Thursday, following a two-day conclave in Vatican City and the death of his predecessor, Pope Francis.

On Saturday, he visited a shrine outside Rome and then prayed before Francis’ tomb inside the basilica of Santa Maria Maggiore.

Pope Leo will be formally inaugurated at a mass in St Peter’s Square next week on 18 May.

Speaking from the central balcony of St Peter’s Basilica, he said: “The immense tragedy of the Second World War ended 80 years ago… now we’re facing the tragedy of a third world war in pieces.

“I would also like to address the powerful people of the world, repeating the always-current call: ‘no more war’.”

The pontiff continued: “I carry in my heart the suffering of the beloved Ukrainian people.

“May whatever is possible be done to reach an authentic, true and lasting peace as quickly as possible. May all the prisoners be freed. May children return to their families.

“And I am deeply hurt by what is happening in the Gaza strip.

“May a ceasefire immediately come into effect. May humanitarian aid be allowed into the civilian population and may all hostages be freed.

He went on: “I was happy to hear on the other hand that there was a ceasefire between India and Pakistan, and I hope that through the coming negotiations we might soon come to a lasting accord.”

His remarks comes as Ukrainian President Volodymyr Zelensky and his Russian counterpart Vladimir Putin set out competing plans for a peace process to bring the three-year invasion of Ukraine to an end.

In the Middle East, Israel has cut off all humanitarian aid entering Gaza and resumed its military offensive in the Palestinian territory following the collapse of a two-month ceasefire and hostage exchange agreement.

Meanwhile, India and Pakistan agreed to a tentative ceasefire on Saturday after days cross-border military strikes that followed an attack on tourists in Indian-administered Kashmir on 22 April.

It has been a busy week for the pontiff, who held his first Mass as Pope in the Sistine chapel on Friday before speaking to cardinals on Saturday.

During this meeting, he described himself as an unworthy choice for Pope, and vowed to continue the “precious legacy” of his predecessor.

He highlighted the importance of missionary work and discussion – as well as care for those he called the “least and the rejected”.

He explained he had chosen the name Leo after a 19th-century Pope known for his teaching on social justice.

The new Pope also suggested the development of artificial intelligence and other advances meant the church was necessary today for the defence of human dignity and justice.

He is due to hold an audience with the media on Monday ahead of his inauguration next Sunday.

As part of that mass he will deliver a homily in the presence of numerous heads of state and dignitaries.

The 69-year-old is the 267th occupant of the throne of St Peter, and the first American to become a pontiff. He will lead members of the Catholic Church’s global community of 1.4bn people.

Born Robert Francis Prevost in Chicago, he worked for many years as a missionary in Peru before being made an archbishop there. He also has Peruvian nationality.

Although Leo was born in the US, the Vatican described him as the second pope from the Americas. Pope Francis, from Argentina, was the first.

Pope Leo is widely seen as a moderate who can offer “continuity” and “unity” following the death of his predecessor last month.

The new pontiff is believed to have shared Francis’ views on migrants, the poor and the environment.

In his first speech he told the crowds he wanted “to walk together with you as a united Church searching all together for peace and justice”.