The UK and its allies will work to fight Russian aggression “wherever and however it might occur”, Prime Minister Boris Johnson said. Mr Johnson spoke to France's President Emmanuel Macron on Saturday, where the two leaders discussed the situation on the Ukrainian border. He updated Mr Macron on his visit to Kiev, where he met Ukrainian President Volodymyr Zelenskiy. “They agreed that finding a diplomatic solution to the current tensions must remain the overriding priority,” a spokesman said. “The prime minister and President Macron stressed that Nato must be united in the face of Russian aggression. They agreed to continue to work together to develop a package of sanctions which would come into force immediately should Russia invade Ukraine. “The leaders discussed their work to strengthen Nato’s eastern flank, ensuring that allies are fully defended against malicious Russian activity, wherever and however it might occur.” Mr Johnson and Mr Macron spoke as European leaders were scheduled to travel to Moscow and Kiev in an effort to calm tensions on the Ukrainian border. Mr Macron is set to visit Moscow on Monday and Kiev on Tuesday, while German Chancellor Olaf Scholz will travel to Kiev on February 14 and Moscow on February 15. British Foreign Secretary Liz Truss is also scheduled to travel to Moscow soon. On Thursday, the US accused the Kremlin of plotting to fabricate an attack by Ukrainian forces that could be used as a pretext for military action. Downing Street said on Friday it has “high confidence” Russia was planning to cook up a reason for incurring on Ukraine's territory. “We have high confidence Russia is planning to engineer a pretext blaming Ukraine for an attack in order to justify a Russian incursion into Ukraine," the Prime Minister’s official spokesman said. “The details in the specific reports today are credible and extremely concerning. We’ve conducted our own analysis on this intelligence and share the US’s conclusion. “We’re considering options for further military deployments to support Nato’s eastern flank, we’re not at the stage of setting out details yet but we will come forward with those in due course.” While France is a major player in Nato and is moving troops to Romania as part of the alliance’s preparation for possible Russian action, <a href="https://www.thenationalnews.com/world/europe/2022/02/02/leaked-cables-show-us-and-nato-open-to-concessions-to-russia/" target="_blank">Mr Macron has also been pushing for dialogue with Russia's President Vladimir Putin and has spoken to him several times in recent weeks. </a> The two will hold a one-on-one meeting Monday, Mr Macron's office said. Germany has emphasised the importance of diplomatic formats in tackling the tensions and has refused to send arms to Ukraine. Russia has amassed more than 100,000 troops near Ukraine’s northern and eastern borders, raising concern that Moscow might invade, as it did in 2014. The Kremlin has denied that an invasion is planned.