The United States expects to achieve its core military objectives in Iran within four to six weeks, White House press secretary Caroline Levitt said on Friday, as Washington claimed growing control over Iranian airspace during the ongoing conflict.

Speaking to reporters at the White House, Levitt said American operations were progressing according to plan and that the goals set by Washington were considered attainable within a short timeframe.

“The United States is well on its way to controlling Iranian airspace,” she said, adding that “achievable American objectives” could be completed within “four to six weeks”.

Levitt also confirmed that discussions were underway in Washington about potential leadership scenarios in Iran, following remarks by President Donald Trump suggesting the United States should play a role in determining the country’s future leadership.

“I know there are a number of people that our intelligence agencies and the US government are looking at, but I won’t go into detail on that,” she said.

Trump had earlier indicated that Iran’s next leader was unlikely to be the son of the late supreme leader Ayatollah Ali Khamenei, who was killed in a strike at the outset of the war and had been widely viewed as a leading successor candidate.

The US president also ruled out negotiations with Tehran unless Iran capitulates completely.

“There will be no deal short of unconditional surrender,” Trump said earlier on Friday.

Levitt later clarified that the administration’s position reflects the military objectives of the campaign.

“What the president means is that when he, as commander in chief, determines that Iran is no longer a threat to the United States and the objectives of Operation Epic Fury have been fully achieved, then Iran will essentially be in a position of unconditional surrender, whether they say so themselves or not,” she said.

Meanwhile, Israel insisted its operations inside Iran are directed solely at military targets after Tehran accused US and Israeli forces of striking civilian infrastructure.

Israeli military spokesman lieutenant colonel Nadav Shoshani said the campaign was conducted “in accordance with international law”, adding that the Israeli military was targeting “only military targets”.

Iranian authorities, however, claimed that hundreds of residential and commercial buildings had been hit since late February, along with several medical facilities, according to statements carried by Iranian state media.