President Joe Biden said on Saturday the United States had delivered a private message to Iran about Houthis responsible for attacking commercial shipping in the Red Sea.
"We delivered it privately and we're confident we're well-prepared," Biden told reporters at the White House before departing to the Camp David presidential retreat for the weekend.
The Houthi movement threatened a "strong and effective response" after the United States carried out another strike in Yemen on Friday night, further ratcheting up tensions as Washington vows to protect shipping from attacks by the Iran-aligned group.
The latest strike, which the US said hit a radar site, came a day after dozens of American and British strikes on Houthi facilities in Yemen.
White House spokesperson John Kirby said on Friday the initial strikes had hit the Houthis' ability to store, launch and guide missiles or drones, which the group has used to threaten shipping.
He said Washington had no interest in a war with Yemen.
Biden, whose administration removed the Houthis from a State Department list of "foreign terrorist organisations" in 2021, was asked by reporters on Friday whether he felt the term "terrorist" described the movement now. "I think they are," Biden said.
Israeli troops and tanks pushed on Saturday into parts of a congested northern Gaza Strip district that they had previously skirted in the more than seven-month-old war, killing and wounding dozens of Palestinians, medics and residents said.
Slovak Prime Minister Robert Fico is no longer in immediate danger but still in a serious condition, his deputy said on Sunday, four days after an assassination attempt that sent shockwaves through Europe.
At least 47 people have died after continued heavy rain and flooding in northern Afghanistan, an official said on Sunday, a day after a similar number were killed in a central province.
Russian airstrikes killed at least ten people and injured many others in a recreation area just outside Ukraine's northeastern city of Kharkiv on Sunday, local officials said.
Saudi Arabia's King Salman bin Abdulaziz will undergo medical tests on Sunday due to "high temperature and joint pain", state news agency SPA reported.