U.S. lawmakers will write legislation requiring the United States to send arms to Ukraine if President Barack Obama does not move to send weapons, Republican Senator John McCain said Thursday.
McCain led about a dozen Republican and Democratic senators at a news conference in pressing Obama to send arms to help Kiev defend itself against a Russian-backed separatist movement.
"We'll be looking at marking up legislation that calls for it," McCain said.
The Senate and House of Representatives unanimously passed legislation in December that authorized sending arms to Kiev. Obama signed the measure into law but it gave him leeway over whether or when to send arms.
Lawmakers have intensified their calls for a strong response from Washington to boost Ukraine.
"This is a fight between a struggling democracy and an autocratic dictatorship and we should take sides," Republican Senator Lindsey Graham said.
In Kiev on Thursday, U.S. Secretary of State John Kerry said Obama would decide soon whether to provide Ukraine with lethal weapons to fight separatists.