"We need to get Brexit done".
Lord Heseltine, who was deputy prime minister under John Major, was more scathing, telling BBC Radio 4's The World Tonight that Conservative MPs needed to decide whether they wanted a repeat of May's election battle with Jeremy Corbyn.
The US and Japan also plan to call for an global ban on oil exports to North Korea in a United Nations Security Council emergency meeting next Tuesday, Japan's Nikkei Asian Review reported.
Also, despite several leading Conservatives thought to be eyeing her job, none appears willing to step in now when Britain is engaged in hard talks to leave the European Union, which officials say are making little or no progress.
Speaking before the tea ceremony, which was followed by a dinner and talks with Abe, May said this model could be used to speed up post-Brexit trade arrangements with other countries.
Asked if she intends to fight the next election, she said: "Yes". She is weakened, she's not a victor.
"Just two days ago, North Korea again went ahead with a reckless act of firing missiles, this time over Japan, and I do hope Japan and the United Kingdom can work together to deal with the threat" from Pyongyang, Abe said at the start of the meeting.
Nicky Morgan, who chairs the Treasury Committee and has been a longstanding critic of Mrs May since being sacked from the Cabinet last summer, said it would be "difficult" for her to lead another election campaign.
"Theresa May leads a zombie government".
The pragmatic Mrs May must surely know her chances of leading the party into a 2022 contest appear vanishingly small at the moment - even assuming her administration stays afloat that long.
"The sooner the public has the chance to vote out her and her government the better for our country's future".
On an official trip to Nigeria, the foreign secretary, Boris Johnson, who is considered a leading contender to replace May, said he supported the prime minster staying on.
"And the in between stage is delivering on some of the stuff we need to deliver". We want the European Union deal to be concluded swiftly.
"And you can't jump straight from that to "I'll go on for ever", you've got to have an in between stage".
"I'm not a quitter", she said.