TEL AVIV, September 16. /TASS/. US Secretary of State Marco Rubio believes that US President Donald Trump may at some point come to a conclusion that it is impossible to settle the Ukraine crisis but so far, the US leader is trying to end the conflict.

Before leaving Tel Aviv for Doha, the US official was asked about "a red line" on Ukraine.

"He's trying to do everything possible to bring it to an end. We've been working closely with our partners in Europe on security guarantees, because that's going to be necessary in any negotiated settlement," Rubio said, adding that Trump believes that peace is possible and he can achieve it.

"At some point, the president may conclude it's not possible. He's not there yet, but he could get to that point. But, you know, he's going to really go the extra mile. There's a way to end this war. He just wants it to stop," the top US diplomat said.

"He's the only leader in the world, the only leader in the world, that can talk to both the Ukrainians, Europeans, and also to the Russians," Rubio added. "He's the only one that can, and he's not going to easily forfeit that role, because he's the only one that can play it," he explained.

On September 15, Trump said he was ready to impose sanctions against Russia, but on condition that Europe does it first, because, according to him, it is unacceptable for Washington to act against Moscow in full, while European countries continued to buy Russian oil.

Another condition is the introduction of 50-100% import duties on China. According to Trump, such measures will help put an end to the Ukrainian crisis, after which the tariffs can be lifted.