Brazilian President Luiz Inácio Lula da Silva has rejected an invitation from his counterpart Vladimir Putin to visit Russia, he said Friday. Lula said Putin invited him over the phone to visit the International Economic Forum in St. Petersburg. 

"I replied I cannot go to Russia right now, but I repeated Brazil's availability to, along with India, Indonesia and China, to talk with both sides of the conflict in search for peace," Lula tweeted.

In turn, Putin said Russia is open "to dialogue on the political and diplomatic track, which is still blocked by Kiev and its Western sponsors," the Kremlin said in a statement Friday, adding the phone call was initiated by the Brazilian side.

The two heads of state also talked about the recent Group of Seven meeting, and about Russian-Brazilian cooperation.

The Kremlin did not mention an invitation to St. Petersburg.

On Thursday, Lula also tweeted he talked on the phone with Chinese President Xi Jinping about the "need for peace in Ukraine."

Some background: Lula has been trying to position himself as a possible mediating force in the conflict for months now.

The Brazilian president has proposed creating “a G20 for peace” — a group of countries strong enough to be respected at the negotiating table, but that are still considered by some as neutral in the conflict between Russia and Ukraine. Indonesia, India, and China would play a crucial role in his vision, but Latin American countries are also invited to join the apparent initiative. He also revealed that during his talks with Xi in April, they discussed forming a group of like-minded leaders on Ukraine.

Lula has struggled to make his proposals widely persuasive. One controversial idea that he floated would see Ukraine cede Crimea, which Russia annexed in 2014, in exchange for peace — a concession Kyiv has ruled out and which the White House described as “simply misguided.”