Yemen's Houthis have said they did not intend to expand their attacks on shipping in and around the Red Sea further, beyond their stated aims of blockading Israel and retaliating against the United States and Britain for air strikes.

In an interview with Reuters, spokesman Mohammed Abdulsalam, who is also the chief Houthi negotiator in peace talks over the country's decade-old civil war, told Reuters the group had no plans to target longstanding foes .

"We do not want the escalation to expand. This is not our demand. We imposed rules of engagement in which not a single drop of blood was shed or major material losses," said Abdulsalam. "It represented pressure on Israel only, it did not represent pressure on any country in the world."

The Iran-aligned Houthis, who control most of Yemen's populated areas, have attacked ships at the mouth of the Red Sea since October, in what they say is a show of solidarity with Palestinians by targeting vessels linked to Israel.

"What the Yemeni people did in the beginning was to target Israeli ships heading to Israel without causing any human or even significant material losses, just preventing ships from passing as a natural right," said Abdulsalam.

"Now, when America joined in and escalated the situation further, there is no doubt that Yemen will respond," he said.

The Houthi attacks have forced international shipping companies to route trade between Europe and Asia around Africa, adding time and costs. The United States and Britain bombed Houthi targets last week in what they called an intervention to keep one of the world's busiest shipping routes open.

"We do not want the conflict to expand in the region and we do not prefer that, and we are still working on non-escalation, but the decision is up to the Americans, as long as they continue to attack," said Abdulsalam.

"Yemen is concerned with responding, and is interested in verifying or maintaining its position by preventing Israeli ships from heading to the occupied Palestinian territories."

The Red Sea conflict is one of half a dozen involving armed groups backed by Iran across the Middle East that have escalated since October, when Hamas fighters attacked Israel provoking an Israeli assault that has since devastated the Gaza Strip.

Washington accuses Tehran - which leads an "Axis of Resistance" including Hamas, Lebanon's Hezbollah and groups in Syria and Iraq - of trying to spread conflict across the region.

Among other flashpoints, Hezbollah and Israel have exchanged fire across the border, while pro-Iranian militias have attacked bases hosting U.S. troops in Iraq.

The Houthis, mountain fighters who captured Yemen's capital a decade ago, have retained their grip through years of war against regional powerhouses Saudi Arabia the UAE, now in a delicate phase of peace talks.

"We do not find justification for taking any action against them, and we call on them to reject the militarization of the Red Sea or the presence of military forces inside the region," Abdulsalam said of the Gulf Arab powers.

Abdulsalam said the Houthis have made their own decisions in the conflict and do not take orders from Tehran, though they maintain a close relationship.

"We have not received any comment from the Iranians until this moment. We do not know if they will inform us later," he said. "Yemen is concerned with responding, and is concerned with confirming or remaining firm on its position of preventing Israeli ships from heading to the occupied Palestinian territories."