"In a line of coherence with the actions in the Ukraine conflict, in which he has already achieved visible successes in terms of the supply of cereals, António Guterres, now promotes new bridges of dialogue between Ukraine and Turkey," reads a note published on the official website of the Presidency of the Republic.

In the note, released on the day that the United Nations secretary-general will meet with the heads of state of Turkey and Ukraine in the Ukrainian city of Lviv, Marcelo Rebelo de Sousa stresses, "once again," the importance of "the role of the Secretary-General of the United Nations, demonstrating the essentiality of the multilateralism of international organisations and the contribution of the UN.”

António Guterres arrived in Lviv yesterday and is due to meet Zelensky and Erdogan today at the Potocki palace in the city centre, after the two heads of state held a bilateral meeting there.

According to the UN secretary-general's office, part of the trilateral meeting is expected to focus on reviewing the functioning of the initiative that enabled the unblocking of grain exports across the Black Sea, signed on 22 July in Istanbul by representatives of the UN, Turkey, Russia and Ukraine. In addition, the UN secretary-general plans to hold a bilateral meeting with the Ukrainian president, in which he is expected to address the general state of the conflict, the need for a political solution and other issues, such as the situation at the Zaporijia nuclear power plant and the attempt to send a mission of international experts to assess it on the ground, Guterres' spokesman Stéphane Dujarric said on Twitter.

On Friday, Guterres will visit Odessa in southern Ukraine, whose port is being used for Ukrainian grain exports through the agreement pushed by the UN itself and Turkey.

Later, the UN chief will travel to Istanbul to visit the Joint Coordination Centre that oversees compliance with that pact, Stéphane Dujarric explained.

Last April, Guterres had been in Ukraine as part of a trip that also included Turkey and Russia, and in which he discussed the evacuation of the besieged Azovstal factory in Mariupol, where Ukrainian military personnel were under siege, which finally took place a few days later, with the support of the UN. During that trip, the grain export agreement, which took months to materialise, also began to take shape.

The military offensive launched on 24 February by Russia in Ukraine has already caused more than 12 million people to flee their homes - more than six million internally displaced and more than six million to neighbouring countries - according to the latest figures from the UN, which classifies this refugee crisis as the worst in Europe since the Second World War (1939-1945). Also, according to the UN, around 16 million people are in need of humanitarian assistance in Ukraine.

The Russian invasion - justified by the Russian President, Vladimir Putin, with the need to demilitarise Ukraine for Russia's security - has been condemned by the international community in general, which is responding by sending arms to Ukraine and imposing sanctions on Russia that affect practically every sector, from banking to energy and even sport.