The relationship between U.S. President Joe Biden and Israeli Prime Minister Benjamin Netanyahu has long been strained over differing outlooks for the future of the Middle East, and has reportedly reached a low point amid Israel's ongoing military offensive against Hamas in Gaza.

Now comes word from a top Biden ally, former Sen. Claire McCaskill (D-MO), that Biden's "most important goal" at the moment is Netanyahu's resignation and ouster from power in Israel, according to Breitbart.

That surprising remark from McCaskill came Tuesday during an appearance on MSNBC's "Morning Joe" during a discussion of the latest controversy over Israeli airstrikes in the Gaza city of Rafah and reports of numerous Palestinian civilian casualties.

Latest controversial strike in Gaza reignites criticism of Netanyahu

"What Hamas wanted more than anything is to isolate Israel. They also wanted to recruit more extreme terrorists to their cause," McCaskill said, according to Breitbart. "When you have something happen like happened over the weekend with these women and children being burned to death in a camp, innocent, that creates more radical terrorists for the Hamas cause."

The former Democratic senator was referring to a deadly incident that occurred on Sunday when a precision bomb was dropped on a Hamas target in Rafah but the resultant explosion ignited a nearby fuel tank and sparked a massive fire in a camp for displaced Palestinians seeking refuge, killing at least 45 and injuring hundreds more, according to CNN.

Israeli PM Netanyahu acknowledged what occurred in a speech on Monday and said, "Despite our best effort not to harm those not involved, unfortunately a tragic error happened last night. We are investigating the case."

Meanwhile, Israel and its leader have faced widespread condemnation and renewed demands from around the world for an immediate halt to its offensive in Rafah, if not a broader ceasefire against Hamas in the entirety of Gaza.

Biden's "most important goal" is ouster of Netanyahu from power

Breitbart reported that on Tuesday's edition of "Morning Joe," co-host Willie Geist asked, "What is the president to do if this continues? He talks about a red line, and there are some who have said in the last 24 hours, if this isn’t a red line, watching what these women and children went through in this camp, many of them killed, what is? How does the president handle Prime Minister Netanyahu right now?"

McCaskil replied, "I think [Biden]’s been trying to do all of this back channel. But the most important goal, I believe, for this presidency right now is to get Netanyahu to resign."

"Netanyahu is holding onto power by his fingernails because of the far-right, who sees the destruction of Gaza in all areas, of any Palestinians in Israel, as their goal. Their goal is very extreme. That’s how he is in power," she continued. "So if he backs up on them, he cannot be in power anymore because he doesn’t have the coalition he needs."

The former senator from Missouri added, "So I think that Biden has to continue to try to press other people in the Israeli government to move as quickly and as strongly as they can to get Netanyahu out of that position."

Biden and Netanyahu's "strained relationship;" Pelosi says Netanyahu "should resign"

Ever since the current Israel-Hamas conflict in Gaza started last October, there have been occasional reports that President Biden and his administration were making secret plans for the removal and replacement of PM Netanyahu -- reports that Biden's White House strongly denied in November, according to The Times of Israel.

Yet, even as the Associated Press reported earlier in May that the strained relationship between Biden and Netanyahu had reached its lowest point ever, it doesn't appear that the American president has publicly called for the Israeli leader's resignation.

At least one prominent U.S. politician has, though, as NBC News reported in April that former House Speaker Nancy Pelosi (D-CA) told an Irish media outlet of Netanyahu, "He should resign. He's ultimately responsible" for what has occurred in Gaza, and added, "I don't know whether he's afraid of peace, incapable of peace, or just doesn't want peace. But he has been an obstacle to the two-state solution."