Former U.N. Ambassador John Bolton called out President Obama's apparent "confusion" about how the United States will respond to worsening violence in eastern Ukraine. 

On the eve of peace talks between Russia, Ukraine, France and Germany, reports indicate that pro-Russian rebels are advancing. 

Obama said he is still considering whether to send weapons to Ukraine, including the option of sending "lethal defensive weapons." 

Bolton took issue with the president's stance, saying on Ukraine, Iran, Syria and other foreign policy decisions, the president always says he's "considering his options."

He questioned "how much of Ukraine will be left" by the time a final decision is made by the White House.

"What is a lethal defensive weapon? Is an M16 a defensive weapon? Is there such a thing as defensive hand grenades? If a weapon is lethal, it's going to be offensive or defensive depending on who's using it. That kind of confusion from the President of the United States encourages Putin and the Kremlin and discourages western Europeans," said Bolton. 

He believes Germany may be prepared to take a harder line against Putin, but Chancellor Angela Merkel is "worried" about what Obama's position will be over the next two years.

"She sees no American leadership. ... I think she's gonna look out for number-one. If the United States isn't gonna lead, she's gonna cut the best deal that she can for Germany."

Watch his full analysis above.