By Beth Rigby, political editor
RAF jets and military assets are being sent to the Middle East after Tehran warned the UK and other allies their regional bases would be targeted if they helped defend Israel in the growing conflict between the two heavily armed countries.
Speaking to reporters on the way to the G7 in Canada, the prime minister refused to rule out provided military support to Israel as it did last October during a ballistic military attack by Tehran.
The UK has not intervened in any military action since Israel strikes began on Friday.
But the prime minister refused to engage on whether the UK would get involved as it did last year when I asked him on the flight to Canada.
"I am not going to get into that," Sir Keir said.
"These are obviously operational decisions and the situation is ongoing and developing and therefore I'm not going to get into the precise details, but we are moving assets, we've already been moving assets to the region, including jets, and that is for contingency support across the region. So that is happening."
Starmer also refused to comment on reports that the UK did not have any advance notice of the Israeli strikes that have trigged the most intense fighting between Tel Aviv and Tehran in decades.
"I'm not going to go into what information we had at the time or since. But we discuss these things intensely with our allies. But I'm not going to get into precisely what we knew, because it鈥檚 a constant flow of information between our allies, and between us and the US," he added.