American forces deployed in Iraq and Syria have been attacked more than 55 times since mid-October, causing minor injuries to dozens of US troops, according to the Pentagon.

The surge in attacks on US troops is linked to the war between Israel and Hamas, which began with a shock cross-border attack by the Palestinian militant group from Gaza on October 7 that Israeli officials say killed about 1,200 people.

In response to the attack, and the capture of around 240 hostages, Israel launched a relentless air, land and naval assault on Gaza, killing about 11,500 people, according to Hamas, which has ruled the Palestinian territory since 2007.

The US Treasury said in a statement it has sanctioned six individuals affiliated with the Iran-aligned Iraqi militia group Ketaeb Hezbollah, and the leader of another Iraq-based group it said was also involved in attacks against US troops in the region.

The Treasury announcement sends a message to Ketaeb Hezbollah and "other Iran-backed groups that the United States will use all available measures to hold to account any opportunistic actors who seek to exploit the situation in Gaza for their own ends," Treasury Under Secretary for Terrorism and Financial Intelligence Brian Nelson said in a statement,

"We remain fully committed to security and stability in the Middle East and are steadfast in our efforts to disrupt these destabilizing activities," he added.

In its statement, the Treasury said Ketaeb Hezbollah was trained, funded, and supported by a branch of Iran's Islamic Revolutionary Guard Corps (IRGC).

Another Iraqi militia involved in attacks against US troops, Kataeb Sayyid al-Shuhada, had also received support from the IRGC, the Treasury said.

There are around 2,500 American troops in Iraq and some 900 in Syria as part of efforts to prevent a resurgence of the Islamic State group.

The jihadists once held significant territory in both countries but were pushed back by local ground forces supported by international air strikes in a bloody, multi-year conflict.