Russian President Vladimir Putin said late Friday that a U.S. proposal for a peace deal in Ukraine could be “the basis” of a resolution to Moscow’s war on Ukraine while warning that if Kyiv rejected the plan then Russian forces would advance farther.

“I believe that it can be used as the basis for a final peaceful settlement,” Putin told senior officials at a meeting of the Russian Security Council, according to media reports.

The 28-point framework titled “U.S.-Russia-drafted peace plan” would confirm Ukraine’s sovereignty but limit its armed forces to 600,000 personnel, hand a significant amount of Ukrainian territory to Russia and bar Kyiv from joining NATO permanently. NATO should agree to “not accept Ukraine at any moment in the future” and “not to deploy its troops in Ukraine,” according to the text.

Putin said Russia is ready to “show flexibility” regarding the settlement proposal, Ukrainian media outlet Ukrainska Pravda reported. Putin said the U.S. proposal is an “upgraded” version of one put forward at the Alaska summit between the Russian and American leaders in August.

“But this text has not been discussed with us in any substantive way,” Putin said, according to other media reports. “Ukraine is against it. Apparently, Ukraine and its European allies are still under illusions and the dream of inflicting a strategic defeat on Russia on the battlefield,” Putin was quoted as saying.

According to the U.S. framework, Russia would commit to not attack again and would be granted reintegration into the global economy, including potential sanctions relief to be discussed “on a case-by-case basis.” Moscow would also be invited to return to the G7 — which was formerly the G8 before Russia was kicked out in 2014 after its illegal annexation of Crimea and military intervention in eastern Ukraine.

Aspects of the proposal were criticized by European and Ukrainian officials on Thursday, claiming that it only favors Moscow and warning that caving in to Russia will only encourage Putin to attack NATO next. 

U.S. President Donald Trump has given Kyiv a deadline of Thanksgiving Day, next Thursday. Ukrainian President Volodymyr Zelenskyy said on Friday that Ukraine faced a “very difficult choice” in considering the U.S. proposal. “Either loss of dignity, or the risk of losing a key partner,” Zelenskyy said, in reference to Washington.

Ukraine’s allies will aim to “strengthen” the U.S. plan at the G20 summit taking place this weekend in South Africa, U.K. Prime Minister Keir Starmer has said. Neither Trump nor Putin is attending the G20 meeting.