Ahead of President Joe Biden’s visit to Israel on Wednesday, Republican lawmakers escalated criticisms of the president over his pick for U.S. ambassador to Israel, policies on Iran, aid to the Palestinians and border security.

Shortly after Biden arrived in Israel, the Senate Foreign Relations Committee was set to hold a confirmation hearing for Jack Lew, the president’s nominee to be U.S. ambassador to Israel; Republicans critical of Lew’s and Biden’s records on Iran were expected to grill Lew.

Foreign Relations Ranking Member Sen. Jim Risch (R-ID) declined to say on Tuesday night whether Republicans would support Democratic efforts to approve Lew’s nomination in the committee before the end of the week, but said Lew has “a lot of baggage” because of his past work on Iran policy.

“We can show support for Israel by filling the ambassadorship, but it has to be the right person,” Risch said. “He’ll have the opportunity to explain his differences with us over Iran [at the hearing], and at that point we’ll see where we are.”

Sen. Joni Ernst (R-IA) was more blunt, joining a growing number of Republicans in opposition to Lew.

“If we really do want an ambassador that will support Israel, we need to find somebody else,” Ernst said. “He has worked too long and too hard with the Iranians. End of story.”

Republicans also introduced a barrage of legislation on Tuesday aiming to force a harder line toward Iran and the Palestinians, and accused the administration of potentially allowing Iran or other foreign adversaries to set up a Hamas-style attack within the United States.

Thirty-one Senate Republicans, led by Sen. Tom Cotton (R-AR) and Minority Leader Mitch McConnell (R-KY), introduced a bill that would override presidential waivers on a range of Iran sanctions — including those that allowed the recent un-freezing of $6 billion in Iranian assets.

Senate Republicans introduced a separate bill to permanently freeze the $6 billion and demand further information from the administration on all other frozen Iranian assets of more than $5 million, with an eye toward legislation blocking any further sanctions relief. The second bill is led by Sen. Tim Scott (R-SC) and co-sponsored by 23 GOP colleagues.

“My bill is a comprehensive approach to wielding our economic sanctions tools against Iran by freezing the $6 billion and ensuring Congress has the information necessary to prevent Iran from accessing funds in the future,” Scott said in a statement. “We must be unequivocal that the United States will not back down and waive sanctions on frozen Iranian funds held by other nations.”

Eleven Senate Republicans, led by Sen. Marsha Blackburn (R-TN), held a press conference at which they leveled further criticism toward Biden over the Iran funds, and called on the administration to cut off all funding to the United Nations Relief and Works Agency (UNRWA). They argued that UNRWA aid was ending up in the hands of Hamas.

“The administration knew that sending U.S. taxpayer dollars to the Palestinians could bolster Hamas,” Blackburn continued. “Yet President Biden has sent them over $730 million in aid since taking office via the U.N. Relief and Works Agency for Palestine Refugees, and yesterday we learned Hamas stole aid from that group.”

Blackburn was referring to social media posts by UNRWA that Hamas officials had forced them out of an UNRWA compound and stolen humanitarian supplies. UNRWA later deleted the posts and denied any theft.

Blackburn and five GOP colleagues introduced a bill that would cut off U.S. funding to UNRWA until Iran is expelled from the U.N. General Assembly and investigated for violating the Genocide Convention.

On the House side, House Foreign Affairs Committee Chairman Michael McCaul (R-TX) joined 24 other lawmakers including members of Republican leadership in introducing legislation seeking to freeze the $6 billion; McCaul also led a letter, with 19 colleagues, to Biden urging the administration to permanently freeze the funds.

Additionally, Republicans are increasingly linking their long-running criticisms of the Biden administration’s southern border policy to the Hamas attack on Israel. They are voicing concerns that Iran or other foreign adversaries could be sending operatives to infiltrate the United States to carry out a terrorist attack similar to Hamas’ surprise attack on Israel.

“As evil regimes like Hamas attack our ally Israel and our adversaries are increasingly emboldened, we should be concerned about terrorist cells moving into the United States,” Sen. Steve Daines (R-MT) said at a Republican leadership press conference on Tuesday — a sentiment that was echoed by other senior Republicans.

Criticism of Biden’s Iran policy is not coming exclusively from Republicans. Democratic Rep. Jared Moskowitz (D-FL), an Iran hawk, joined with Rep. Claudia Tenney (R-NY) on Tuesday to send a letter to Biden urging a change in his Iran policy.

They argued Iran is “unwilling to reciprocate diplomatic gestures or financial inducements with anything other than more regional aggression and bloodshed,” so the U.S. should end efforts to reenter the Iran nuclear deal and enforce all sanctions on Iran, among other steps.