US President Joe Biden, Vice President Kamala Harris and other officials marked the first anniversary of the Hamas militant group's deadly attack on Israel on Monday, mourning the death of victims and calling for the return of hostages and a ceasefire in Gaza.

They issued separate statements, taking stock of what has happened since Hamas militants killed more than 1,200 people, including 46 Americans, and took over 250 people hostage, including 12 Americans, in the Oct. 7 attack.

"One year later, Vice President Harris and I remain fully committed to the safety of the Jewish people, the security of Israel, and its right to exist," Biden said. "We support Israel's right to defend itself against attacks from Hezbollah, Hamas, the Houthis, and Iran."

For Palestinians, history will remember Oct. 7 as a "dark" day because of the conflict unleashed by Hamas, the president said. Palestinian health authorities have said that Israel's military offensive in Gaza has left more than 41,000 people dead, according to reports.

"Far too many civilians have suffered far too much during this year of conflict -- and tens of thousands have been killed, a human toll made far worse by terrorists hiding and operating among innocent people," he said.

"We will not stop working to achieve a ceasefire deal in Gaza that brings the hostages home, allows for a surge in humanitarian aid to ease the suffering on the ground, assures Israel's security, and ends this war. Israelis and Palestinians alike deserve to live in security, dignity, and peace."

In her statement, Harris, the Democratic presidential nominee, vowed to do "everything" in her power to ensure that "the threat Hamas poses is eliminated, that it is never again able to govern Gaza, that it fails in its mission to annihilate Israel, and that the people of Gaza are free from the grip of Hamas."

"I will always ensure Israel has what it needs to defend itself against Iran and Iran-backed terrorists like Hamas," she said. "My commitment to the security of Israel is unwavering."

Harris also said that she was "heartbroken" over the scale of death and destruction in Gaza over the past year.

"It is far past time for a hostage and ceasefire deal to end the suffering of innocent people," she said. "And I will always fight for the Palestinian people to be able to realize their right to dignity, freedom, security, and self-determination."

Secretary of State Antony Blinken renewed calls for a ceasefire.

"It is time to reach a ceasefire agreement that brings the hostages home, alleviates the suffering of the Israeli and Palestinian people, and ultimately brings an end to this war," he said.

He also called for the international community to stand "steadfast" in the face of terrorism and violent extremism, and to condemn Iran's support for Hamas and other groups in the Middle East.

"On this painful anniversary, the United States stands with Israel as it defends itself against terrorism," he said. "We remain steadfast in our commitment to lasting peace and stability across the region and for a common future for Israelis and Palestinians with equal measures of security, dignity, opportunity, and freedom."

Defense Secretary Lloyd Austin reaffirmed America's commitment to Israel's security, while stressing the need for Israelis and Palestinians to find a path toward a two-state solution as part of a "broader, brighter future of Arab-Israeli normalization that includes Israel's integration into the region."

"The Department of Defense will not flinch in our commitment to Israel's security, to combating terrorism by Hamas and other fanatical groups, to deterring further aggression from Iran, and to working with our allies and partners to promote stability and peace in the Middle East," Austin said.

"My prayers today are with those murdered by Hamas on October 7th, with the survivors, and with all who are still working courageously to bring their loved ones home and end the suffering by reaching a ceasefire deal that will bring the hostages home and enable a surge of humanitarian aid."

Meanwhile, the Department of the Treasury issued sanctions on three individuals and one sham charity that are prominent international financial supporters of Hamas, as well as one Hamas-controlled financial institution in Gaza. It also designated a longstanding Hamas supporter and nine of his businesses.

"As we mark one year since Hamas' brutal terrorist attack, Treasury will continue relentlessly degrading the ability of Hamas and other destabilizing Iranian proxies to finance their operations and carry out additional violent acts," Secretary of the Treasury Janet Yellen said.

"The Treasury Department will use all available tools at our disposal to hold Hamas and its enablers accountable, including those who seek to exploit the situation to secure additional sources of revenue."

The campaign of Republican presidential nominee Donald Trump also released a statement, arguing that the Oct. 7 atrocities "would have never happened" if Trump had been in the White House.

"For Americans and Israelis alike, it's imperative that President Trump is re-elected so he can end the bloodshed caused by an emboldened Iranian terrorist regime, which is stronger and richer today from the Harris-Biden Administration's incompetence and weak policies," Karoline Leavitt, the national press secretary of Trump's campaign, said. (Yonhap)