Boris Johnson officially became the United Kingdom's new prime minister Wednesday after meeting with the queen.

Johnson, an ardent Brexit supporter, used his first public remarks as prime minister to vow that the U.K. would leave the European Union on Oct. 31, "no ifs or buts."

The newly minted prime minister also said he would push to secure "a new deal, a better deal" from the EU on Brexit.

Johnson, who previously served as the U.K.'s foreign secretary, won the Conservative Party's leadership vote on Tuesday to become prime minister, succeeding Theresa May Theresa Mary MayAre US-Japan relations on the rocks? Trump insulted UK's May, called Germany's Merkel 'stupid' in calls: report Bolton says Boris Johnson is 'playing Trump like a fiddle' MORE.

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“We will maximize the opportunities of Brexit while allowing us to develop a new and exciting partnership with the rest of Europe based on free trade and mutual support,” Johnson said.

“I have every confidence that in 99 days time we will have cracked it. But you know what, we are not going to wait 99 days, because the British people have had enough of waiting.”

Johnson, without detailing a plan, attempted to quell reservations from opponents of Brexit.

He said he is “convinced” that the U.K. can negotiate a deal without checks at the Irish border.

He also said various industries, including ports, banks, businesses and hospitals, will be ready to leave the EU.

“And to all those who continue to prophesy disaster, I say 'yes, there will be difficulties,' though I believe with energy and application they will be far less serious than some have claimed,” he said.

While reiterating his confidence that a deal can be negotiated, Johnson said he will prepare for the “remote possibility that Brussels refuses any further to negotiate,” referring to the EU headquarters.

“We are forced to come out with no deal not because we want that outcome, of course not, but because it is only common sense to prepare,” he said.

British leaders have failed to negotiate a deal for the U.K. to leave the EU since a 2016 referendum in favor of Brexit.

Then-Prime Minister David Cameron resigned after the vote, and subsequent Conservative Party members in power have not been successful at negotiating the controversial deal.

Updated: 11:40 a.m.