He will set the goal out at Cop29 later on Tuesday, but it has been reported the UK will pledge to reduce emissions by 81% compared with 1990 levels by 2035, in line with the recommendation of the Climate Change Committee.
The Prime Minister was asked if he was prepared to get more people to change their heating systems and tell them to take fewer flights and eat less meat to reach that target.
"I'll set out our goal later on today, but look, it will be ambitious, and that's measured not by telling people what to do.
"It's measured by making sure that we get to clean power by 2030 - that's the single most important target on the way to the emissions.
"And that will bring with it lower bills for people, for their energy it'll give them independence, so that tyrants like (Vladimir) Putin can't put his boot on our throat, causing all sorts of difficulties for our energy bills," the Prime Minister told broadcasters in Baku.
He said the target was "difficult" but "achievable", adding: "But it's not about telling people how to live their lives. I'm not interested in that. I am interested in making sure that their energy bills are stable, that we've got energy independence, and that we also, along the way, pick up the next generation of jobs."
A £1 billion order for blades for offshore wind turbines to be made in Hull has been secured, he said.
The Prime Minister also plans to push the private sector to "start paying their fair share" when it comes to climate commitments.
The climate conference in Azerbaijan comes days after the re-election of Donald Trump, who is expected to boost fossil fuels, roll back green incentives domestically and pull his country out of the Paris climate agreement again.
Sir Keir said he would not comment on Mr Trump when asked if he was prepared to call out the president-elect about his claims that climate change is a hoax, saying: "I'm not going to comment on his views. I am very clear in mine."
The Prime Minister has said he sees action on climate change as not just an obligation, but an opportunity.
"The UK has a huge opportunity to get ahead here when it comes to renewables," he said.
"That's why I'm encouraging as much investment as I can when it comes to carbon capture, when it comes to hydrogen, when it comes to offshore wind.
"There's a global race on now to be the global leader on this. I want us to be in the race and I want us to win the race."
Wealthier countries are facing pressure over delivering finance to help poor countries cope with climate change, and increasing their ambitions on emissions cuts.
One hundred billion dollars (£77 billion) a year was pledged in private and public finance to help poorer nations, as part of efforts to secure the Paris treaty negotiated in 2015.
But wealthier nations must now iron out a new finance agreement that meets the Paris commitments for sufficient cash flows for cutting emissions and adapting to climate change, with experts saying one trillion US dollars needs to be flowing into developing countries each year by 2030.
In 2019, the Tories pledged £11.6 billion to help poorer countries deal with climate change over five years to 2025/26.
The Labour Government will honour that commitment, but the Prime Minister has said it will not be unveiling new UK commitments to climate finance through to 2035.
He told journalists on the way to Baku: "This exercise is not about domestic countries and the contribution they're making, that's about the Cop arrangement for what the sum will be to 2035. So I'm not making any commitment for the UK at this Cop at all on that front."
At the summit, Sir Keir will argue that the climate transition presents an almost seven trillion-dollar (£5.43 trillion) investment opportunity.
The Government estimates that supplying the goods and services to enable the global net-zero transition could be worth £1 trillion to UK businesses by 2030.
Foreign Secretary David Lammy and Energy Secretary Ed Miliband have also travelled to Azerbaijan.
The Government is also launching a new CIF Capital Market Mechanism on the London Stock Exchange which it says could mobilise up to 75 billion dollars (£58 billion) in additional climate capital for developing countries over the next decade.
"I will be making an argument powerfully that now is the time for the private sector to start paying their fair share in relation to these commitments," Sir Keir said.
He said they would be launching the initiative because "I think it's high time the private sector played their part in this".
Sir Keir will hold a one on one meeting with the president of the World Bank on the fringes of the summit on Tuesday.