Ukrainian President Volodymyr Zelensky pleaded for 'life and death' aid to continue his country's fight against Russia, telling senators at a closed briefing his citizens would resort to 'guerilla war' if needed and support dries up.

The president met with Senate leaders, House Speaker Mike Johnson, and pitched an all senators briefing in an extraordinary lobbying push amid declining support for the Biden administration's policy of bolstering Ukraine's defense. 

'The president did mention at some point in time guerrilla warfare, if he doesn't get the kind of support – if it degraded [to] that point,' Wisconsin Sen. Ron Johnson told a group of reporters after the meeting.

'I mean, Putin would be facing a long term guerrilla war in whatever parts of Ukraine you'd occupy that can't be particularly attractive for him,' he said.

Biden has proposed a $61 billion aid package, but Republicans in the House and Senate are rallying around a demand require border policy changes. They note that Biden included Border requests in his request for supplemental emergency funds. 

'I know that everybody wants Ukraine to win. I just don't see that in the cards,' said Johnson, in some of the more pessimistic comments to come out of the meeting. 'As evil as [Russian President Vladimir] Putin is, as violated as Ukraine is, you have to look at the reality of the situation. Ukraine can't do what it would need to do to bring Russia to her knees,' he said. 

He said if lawmakers 'really think this is such a huge point in history and so vital to provide Ukraine [$61 billion] worth of aid, they have to look at the clear and present danger of our unsecure border or open border and fix that. We'd be doing them enormous political favor for just forced them to do that.' 

'It boggles my mind that they don't understand how dangerous this is for America to have that open border and truthfully what a political liability it is. There's a deal to be done here,' he added.