The US is expected to warn the Kremlin that it will “arm Ukraine to the teeth” if Russia does not accept an immediate 30-day ceasefire, British security sources have claimed.

The move comes after Ukraine said it was ready to accept a temporary 30-day ceasefire with Russia, proposed by the US after talks in Saudi Arabia.

US Secretary of State Marco Rubio said he would present the offer to Russia and that “the ball is in their court” — Moscow is yet to publicly comment on the issue.

Ukraine’s President Volodymyr Zelensky said it was now up to the US to convince Russia to agree to the “positive” proposal.

But a senior security source told National Security News that US President Donald Trump will make it clear to President Vladimir Putin that he expects Russia to sign up to the deal.

The source said: “Trump will not want this deal to fail. He will make it clear to the Russian leader that he expects Putin to get on board. If Putin refuses to accept the deal, then Trump will make it clear that the US will back Ukraine — that could mean arming Ukraine to the teeth. That means intelligence cooperation, better weapons, better equipment — everything Ukraine needs to hold off Russia.”

In a joint statement with Ukraine, the US also said it would immediately restart intelligence sharing and security assistance to Ukraine, which Washington had suspended after the unprecedented public row at the White House.

“Both delegations agreed to name their negotiating teams and immediately begin negotiations towards an enduring peace that provides for Ukraine’s long-term security,” the US-Ukraine statement said.

Rubio also said that he hoped Russia would accept the proposal.

Ukraine was “ready to stop shooting and start talking,” he said, and if Russia rejected the offer, “then we’ll unfortunately know what the impediment is to peace here.”

“Today we made an offer that the Ukrainians have accepted, which is to enter into a ceasefire and into immediate negotiations,” he said.

“We’ll take this offer now to the Russians, and we hope they’ll say yes to peace. The ball is now in their court,” he added.

Trump’s special envoy, Steve Witkoff, who was at the Jeddah talks, is expected to travel to Russia in the coming days.

The offer of a 30-day ceasefire goes beyond Zelensky’s proposal for a partial truce in the sky and at sea.

The Ukrainian president thanked Trump for “the constructiveness” of the talks in Jeddah.

In a video message, Zelensky said Russia had to “show its willingness to stop the war or continue the war.”

“It is time for the full truth,” he added.

The Kremlin has not yet publicly responded. It said earlier on Tuesday that it would issue a statement after being briefed by Washington on the outcome of the talks.

But influential Russian lawmaker Konstantin Kosachev said that any potential agreements would be “on our terms, not American.”

Kosachev, chairman of the Federation Council’s international affairs committee, said, “Real agreements are still being written… at the front,” stressing that Russian troops were advancing in Ukraine.

At the White House, Trump told reporters he would speak with Russian President Vladimir Putin, who would “hopefully” agree to the proposal.

“It takes two to tango, as they say,” Trump said, adding that he hoped the deal would be agreed upon in the next few days.

“We have a big meeting with Russia tomorrow, and some great conversations hopefully will ensue.”

He added that he was open to inviting Zelensky back to Washington.

Russian Foreign Ministry spokeswoman Maria Zakharova said Russia had not ruled out talks with US representatives in the next few days, according to Russia’s state-owned news agency Tass.