An adviser to Ukraine’s president has challenged Russia to conduct an urgent round of talks in Mariupol.

Mykhailo Podolyak, an adviser to President Volodymyr Zelenskyy, said on Twitter that he and other Ukrainian negotiators are ready for any format of negotiations to save lives of Mariupol defenders and civilians trapped in the city.

He tweeted that “we’re ready to hold a “special round of negotiations” right in Mariupol. One on one. Two on two.”

Podolyak said that Ukraine is ready for talks without any conditions “to save our guys, Azov, military, civilians, children, the living and the wounded. Everyone. Because they are ours. Because they are in my heart. Forever.”

There was no immediate response from Russia to Podolyak’s offer.

Mariupol has faced a Russian siege and relentless bombardment for seven weeks, and the last remaining Ukrainian defenders are currently trapped at a giant steel mill encircled by the Russians. They have rejected the Russian ultimatum to surrender or get killed.

Zelenskyy said up to 1,000 civilians could be trapped at the Azovstal steel plant.