General Sir Patrick Saunders, who took over Monday from General Sir Mark Carleton Smith as the Army’s chief of staff, said his “sole task” would be to “make our Army as deadly and effective as it can be”. He told the troops in a message: “We are the generation that must prepare the Army to fight in Europe once again. There is now an ardent need to create an Army capable of fighting alongside our allies and defeating Russia in battle. “I am the first Chief of General Staff since 1941 to take command of the Army in the shadow of a land war in Europe involving a continental power. “Russia’s invasion of Ukraine underscores our main goal – to protect the United Kingdom by being ready to fight and win wars on land.” The government set plans last year to reduce the size of the regular Army, reducing the size of the staff from 82,000 to 72,500 by 2025. “We must be prepared for (the war in Ukraine) to last for years,” NATO chief Jens Stoltenberg told the German newspaper Bild on Sunday. He said: “We must not weaken our support for Ukraine, even if the costs are high – not only in terms of military support but also because of rising energy and food prices. “This is not comparable to the price Ukrainians have to pay every day. “And if Putin learns from this war that he can just continue as he did after the 2008 war in Georgia and the occupation of Crimea in 2014, then we will pay a much higher price.” Mr Stoltenberg added: “NATO will continue to support Ukraine in its self-defense, but it is not part of the conflict. We are helping the country, but we will not send NATO troops to Ukraine. “We have strengthened our defense, with 40,000 troops under NATO command. We secure the territory of the alliance on land, at sea and in the air. “This is a clear message to Moscow so that there are no misunderstandings about our readiness.” It comes after the Prime Minister returned from Ukraine with a warning that “we must arm ourselves for a long war.” After his visit to Kyiv, Boris Johnson said that Vladimir Putin’s invasion “is entering a new phase” and that if Russian progress is successful, “it will not stop dividing Ukraine.” Writing to the Times, Mr Johnson said: “I’m afraid we have to arm ourselves for a long war as Putin launches a campaign of destruction, trying to crush Ukraine with sheer barbarism. “The United Kingdom and our friends must respond by ensuring that Ukraine has the strategic stamina to survive and ultimately prevail.” “Everything will depend on whether Ukraine can strengthen its ability to defend its territory faster than Russia can renew its ability to attack,” he added. “Our task is to spend time on the side of Ukraine.”