The push to finalize a ceasefire and hostage deal in Gaza has reached a "decisive moment," the United States' top diplomat said Monday as Hamas and the Israeli prime minister expressed skepticism about progress in talks. This is "probably the best, maybe the last, opportunity to get the hostages home, to get a ceasefire and to put everyone on a better path to enduring peace and security," US Secretary of State Antony Blinken said in a news conference alongside Israeli President Isaac Herzog in Tel Aviv before the two met. "It is time for everyone to get to yes, and to not look for any excuses to say no," Blinken said. "It is time for it to get done. It's also time to make sure that no one takes any steps that could derail this process." Shortly after meeting the Israeli president, Blinken drove to Jerusalem to meet Prime Minister Benjamin Netanyahu. He is also slated to meet with Israeli Defense Minister Yoav Gallant. The death toll in Gaza since Israel started its war against Hamas passed 40,000 this week, just as mediators arrived in Doha to discuss a ceasefire. A new ceasefire plan drawn up by the US, Qatar and Egypt was presented on Friday following two days of high stakes talks in Doha. The mediators have been stepping up efforts as the Middle East braces for a possible Iranian attack on Israel, and after the death toll since October in Gaza reached 40,000 people — a bleak figure that underscores 10 months of suffering, malnutrition and despair in the Palestinian enclave during Israel's war with Hamas. Blinken's visit has become an established pattern of traveling for in-person meetings to project high-level public pressure around the need for an agreement. On Monday, he said he was in Israel as "part of an intensive diplomatic effort on President (Joe) Biden's instructions to try to get this agreement to the line and ultimately over the line." Blinken did not say the onus was specifically on Hamas to accept the deal – he did not mention the group at all. US officials have voiced optimism about the prospects of the "bridging proposal." However, on Sunday evening, Hamas and Netanyahu traded accusations suggesting that a deal may still be far off. Hamas said the latest proposal made following discussions between mediators in Doha didn't include a permanent ceasefire and introduced new conditions on the exchange of prisoners, among other issues. The group blamed Netanyahu for "obstructing" a deal from being reached and reiterated its desire to enact a three-phase proposal presented by US President Joe Biden, which would include the release of hostages from Gaza, a "full and complete ceasefire," and the release of Palestinian prisoners held in Israel. It called on mediators to "compel the occupation to implement" that plan. Netanyahu shot back, saying Israel will not be "giving in to Hamas's demand" to end the war in Gaza as a condition of a deal. "The Prime Minister has strongly insisted on this fundamental demand, which is vital to achieving the goals of the war, and Hamas changed its position," a statement from his office said Sunday. "The Prime Minister will continue to work on advancing a deal that will maximize the number of living hostages and which will enable the achieving of all of the war objectives." Other key sticking points in talks include Israel's insistence on controlling the border between Gaza and Egypt, having a veto over which Palestinian prisoners are released and preventing the movement of armed men from southern Gaza to the north. Despite the negative rhetoric, US President Joe Biden on Sunday said he believed a deal is "still possible." "We're not giving up," Biden told reporters. A US official said Monday that talks are still expected to resume this week as planned. Speaking alongside Herzog on Monday, Blinken acknowledged it is a "fraught moment" for Israel over concerns about the possibility of attacks from Iran and its proxies, including Hezbollah in Lebanon, and said the US has "taken decisive actions... to deter any attacks and if necessary to defend against any attacks." "We're working to make sure that there is no escalation, there are no provocations, that there are no actions that in any way could move us away from getting this deal over the line, or, for that matter, escalating the conflict to other places and to greater intensity," he said. Echoing statements made by Netanyahu, Herzog blamed Hamas for the deal not yet being finalized, saying "people have to understand it starts with the refusal of Hamas to move forward." The Israeli president expressed optimism. "We are simply still very hopeful that we can move forward in the negotiations that are held by the mediators," he said. On Sunday, the Hostages and Missing Families Forum said the Israeli government is "dragging its feet" and accused the prime minister of not doing "everything in their power to return the hostages." This is the ninth trip Blinken has made to the region since the October 7 Hamas attack on Israel. As Blinken arrived in Israel on Sunday, there was an explosion in Tel Aviv that Israeli officials declared to be a terror attack. Hamas' armed wing, Al-Qassam Brigades, claimed responsibility for the explosion. In the evening, an Israeli airstrike in central Gaza killed seven members of the same family, medical officials said. Six children and their mother were killed in the strike on a home in Deir al-Balah, according to the Al-Aqsa hospital. The children's father was injured, a hospital spokesperson said. It comes just a day after an Israeli strike killed at least 15 people, all from the same family, in the al-Zawayda area of Deir al-Balah in central Gaza. Nine children were among those killed, according to the Gaza Civil Defense. In a statement Sunday, the Israeli military said forces continue to operate in Khan Younis and Deir al-Balah. Adding to Gazans' woes, doctors last week detected the first case of polio in the enclave in 25 years. — CNN