Ukrainian President Volodymyr Zelensky on Monday declared that Wednesday will be a national day of unity.

Choosing Feb. 16 is no coincidence — several U.S. officials told Politico on Friday that intelligence seems to point at Russia launching an attack against Ukraine on that day. Zelensky’s office released a decree calling on every town and village in Ukraine to fly the country’s flag, with all residents singing the national anthem at 10 a.m.

Russia has an estimated 130,000 troops and heavy weaponry stationed around its border with Ukraine, and while Zelensky has said he does think Russia is being threatening, he does not believe an invasion is imminent. In a video address on Monday, Zelensky stated, “They tell us Feb. 16 will be the day of the attack. We will make it a day of unity. They are trying to frighten us yet again naming a date for the start of military action. On that day, we will hang our national flags, wear yellow and blue banners, and show the whole world our unity.”

On Sunday, U.S. National Security Adviser Jake Sullivan told CNN Russia could invade Ukraine “any day now,” and that “includes this coming week.” Secretary of State Antony Blinken on Monday had U.S. embassy staff temporarily relocate from Kyiv to Lviv in western Ukraine, due to the “dramatic acceleration in the buildup of Russian forces.” While speaking to reporters, Pentagon spokesman John Kirby said he didn’t want to discuss any specific dates, because “I don’t think that would be smart. I would just tell you that it is entirely possible that [Russian President Vladimir Putin] could move with little to no warning.”

Russia has said it has several security concerns that it wants addressed by the West and NATO, and wants Ukraine to be permanently barred from joining NATO. The United States and its allies have warned of harsh sanctions if Russia invades Ukraine, and on Monday, Russian Foreign Minister Sergei Lavrov told Putin during a televised exchange that there is still hope for diplomacy, and “it seems to me that our possibilities are far from exhausted.”