President Donald Trump’s Friday deadline has arrived for Russia’s Vladimir Putin to agree to a ceasefire with Ukraine or face “secondary sanctions” against countries that buy oil from Russia.

But uncertainty remains as to whether the U.S. will hit Moscow with new economic penalties amid talk of a possible bilateral meeting between Trump and Putin happening soon.

Trump on Thursday was asked directly if his Aug. 8 deadline for Putin to make peace or face consequences still applied.

“It’s gonna be up to him,” the president responded. “We’re going to see what he has to say. It’s gonna be up to him. Very disappointed.”

The White House is pushing for a trilateral summit between Trump, Putin and Ukrainian President Volodymyr Zelenskyy, though Trump said Putin meeting with Zelenskyy wasn’t a condition for he and Putin to meet.

“They would like to meet with me and I’ll do whatever I can to stop the killing,” Trump said on Thursday.

Trump, who once said he could end the Russia-Ukraine war within his first 24 hours in office and touted his personal relationship with Putin, has expressed increasing frustration with the Russian leader.

In mid-July, Trump said he was giving Putin a 50-day ultimatum to stop the fighting. He then moved up the timeline to 10 days, citing his disappointment with Putin.

“I want to be generous, but we just don’t see any progress being made,” Trump said at the time. “I’m not so interested in talking anymore. He talks, we have such nice conversations, such respectful and nice conversations, and then people die the following night in a — with a missile going into a town and hitting.”

Tensions between the U.S. and Russia escalated last week when Trump announced he was moving nuclear submarines in response to what he called “highly provocative statements” from the deputy chair of Russia’s security council, Dmitry Medvedev.

Medvedev, also the former president of Russia, had sounded off on Trump’s ceasefire deadline, writing on social media that “each new ultimatum is a threat and a step towards war.”

While Trump said the nuclear submarines would be moved in response, he and the White House would not specify what capabilities the submarines have or other questions surrounding the announcement.

And earlier this week, Trump indirectly upped the pressure on Russia by doubling his tariff rate against India over India’s imports of Russian oil.