President Joe Biden said Tuesday that Congress will be doing the Kremlin's bidding if it fails to renew funding for Ukraine's fight against Russian invasion -- and blamed Donald Trump for playing politics with US national security.
The "clock is ticking" for Ukraine, Biden warned.
The US president called out Trump -- his expected November election rival -- for pressuring Republican lawmakers not to pass a $118 billion bill that would fund Ukraine's military in return for strict US immigration curbs, a Republican demand.
"We can't walk away now. That's what Putin's betting on," Biden said. "Supporting this bill is standing up to Putin. Opposing this bill is playing into his hands."
The immigration portion of the legislation, he said, included the "toughest set of reforms to secure the border ever."
Despite themselves insisting on the immigration crackdown as a condition for renewing US aid to pro-Western Ukraine, Republicans have now responded to Trump's pressure by making clear they will not help Democrats pass the huge bill.
This will sink Ukraine's chances of getting desperately needed weaponry and ammunition as it enters the third year of resisting a full-scale Russian invasion.
It also means that the toughly negotiated measures to harden the US-Mexican border and keep out undocumented migrants will be abandoned, despite getting initial approval from senior Republican and Democratic senators.
- 'They're caving' -
"Most of our members feel that we're not going to be able to make a law here," top Senate Republican Mitch McConnell acknowledged to journalists Tuesday.
Biden said Trump, who is running for a return to the White House largely on his anti-immigrant platform and claims that the southern border is suffering an "invasion," was using the crisis to boost his electoral chances.
"Donald Trump thinks it's bad for him politically. Therefore... even though it helps his country, he's not for it," Biden said. "He'd rather weaponize this issue than actually solve it."
"For the last 24 hours he has done nothing, I'm told, but reach out to Republicans in the House and the Senate and threaten them and try to intimidate them," Biden said. "It looks like they're caving."
Trump has been ramping up attacks on the bill for weeks, undermining his own party's leaders as they inched toward compromise on the border -- and thereby opening the door to Ukraine aid.
Biden's speech on the bill "was an embarrassment to our nation and a slap in the face to the American people," Trump spokeswoman Karoline Leavitt said in a statement, adding that under the ex-leader the border was the most secure "in American history."
Biden and Trump are campaigning on starkly divergent approaches to Ukraine, with the Democrat clear that helping the pro-Western ally repel Russia is vital to ensure a safer world while his predecessor pushes an isolationist "America First" policy.
At home, Biden has pressed for a humane immigration policy but Republicans point to statistics showing migrant apprehensions reaching a record high of 302,000 in December, a surge Trump has been wielding as a major issue in the campaign.
The bipartisan deal, unveiled by senators Sunday, is a $118 billion package of immigration restrictions that Biden has committed to signing into law. It is tied to a foreign aid package that includes $60 billion for Ukraine and $14 billion for Israel.