U.S. President Donald Trump offered on Monday to join prospective Ukraine-Russia talks in Turkey later this week as European countries pushed to get the Kremlin to accept their demand for a 30-day ceasefire in the war in Ukraine, Reuters reported.

Trump spoke a day after Ukrainian President Volodymyr Zelenskiy, in a fresh twist to the stop-start peace talks process, said he would travel to Istanbul where, he said, he would be waiting to meet Russian counterpart Vladimir Putin.

Trump told reporters at the White House that talks in Istanbul could be helpful and he might join them on Thursday while in the region. His current schedule has him visiting Saudi Arabia, the United Arab Emirates and Qatar this week.

“I’ve got so many meetings, but I was thinking about actually flying over there. There’s a possibility of it, I guess, if I think things can happen, but we’ve got to get it done,” he said before departing for his second foreign trip since his second term in the White House began in January, read the report.

“Don’t underestimate Thursday in Turkey,” Trump said.

Later, in his nightly video address, the Ukrainian president noted that Russian attacks had continued on the front lines throughout the day, and Moscow still had not responded to his call for Putin to meet him for talks in Turkey later in the week.

“Russian shelling and assaults continue,” Zelenskiy said. “Moscow has remained silent all day regarding the proposal for a direct meeting. A very strange silence.”

Diplomatic contacts were renewed.

Zelenskiy and Turkish President Tayyip Erdogan discussed the proposed direct talks which Zelenskiy said “may help end the war”. Erdogan described the proposed meeting as a new window of opportunity which was not to be squandered.

Russian Foreign Minister Sergei Lavrov spoke by telephone with his Turkish counterpart Hakan Fidan about Putin’s proposed talks with Ukraine on Thursday. But a brief Russian foreign ministry account gave no indication whether Putin would accept Zelenskiy’s proposal to meet him, Reuters reported.

Earlier on Monday, the German government said Europe would start preparing new sanctions against Russia unless the Kremlin by the end of the day started abiding by a 30-day ceasefire in its war with Ukraine.

Ukraine’s military said Russia had conducted dozens of attacks along the front in eastern Ukraine on Monday as well as an overnight assault using more than 100 drones, despite the ceasefire proposal by Europe and Kyiv.

“The clock is ticking,” a German government spokesperson said at a news conference in Berlin.

Russian Foreign Ministry spokeswoman Maria Zakharova said the 30-day ceasefire had been put forward by European countries “in order to provide a breather for Kyiv to restore its military potential and continue its confrontation with Russia.”

It is unclear, though, how much impact fresh European sanctions would have on Russia, especially if the United States does not join in as well.

The leaders of four major European powers travelled to Kyiv on Saturday and demanded an unconditional 30-day ceasefire from Monday. Putin, implicitly rejecting the offer, instead proposed direct Russia-Ukraine talks in Istanbul that he said could potentially lead to a ceasefire, read the report.

Putin and Zelenskiy have not met since December 2019 – over two years before Russia launched its full-scale invasion of Ukraine – and make no secret of their contempt for each other.

Responding to the ceasefire proposal, Russia said at the weekend it is committed to ending the war but that European powers were using the language of confrontation.

Ukrainian Foreign Minister Andrii Sybiha said Russia was “completely ignoring” the ceasefire initiative, citing what he said were continued attacks on Ukrainian forces.

He said he shared information about the continued fighting with European partners and U.S. Secretary of State Marco Rubio on a joint phone call. The allies had agreed sanctions would be needed to pressure Russia if it snubbed the truce move.

Russia and Ukraine are both trying to show Trump they are working towards his objective of reaching a rapid peace in Ukraine, while trying to make the other look like the spoiler to his efforts.

The Ukrainian military’s general staff said that as of 10 p.m. (1900 GMT) on Monday there had been 133 clashes with Russian forces along the front line since midnight, when the ceasefire was to have come into effect.

Ukraine’s top commander, Oleksander Syrskyi, was quoted by Zelenskiy as saying the heaviest fighting still gripped the Donetsk region, the focus of the eastern front, and Russia’s western Kursk region, nine months after Kyiv’s forces staged a cross-border incursion.

The fighting was at the same intensity it would be if there were no ceasefire, said Viktor Trehubov, a spokesperson for the military on Ukraine’s eastern front.

Kyiv is desperate to unlock more of the U.S. military backing it received from Trump’s predecessor, Joe Biden. Moscow senses an opportunity to get relief from a barrage of economic sanctions and engage with the world’s biggest economy.