The Taliban say the Aug. 31 deadline for the withdrawal of international troops from Afghanistan is a "red line" and that no extension will be allowed. US President Joe Biden said on Sunday that personnel may need to stay beyond that date to continue the evacuation of all Americans. Britain is urging Washington to extend the evacuation and Prime Minister Boris Johnson plans to press Biden at an emergency G7 meeting on Tuesday. But Taliban spokesman Suhail Shaheen has said that such a move by the US or the UK would mean "they are extending occupation" and would bring "consequences", creating "mistrust" between the two sides. The UK’s defense secretary said on Monday the government would make the case for extending the evacuations of people from Afghanistan beyond the the August deadline agreed with the Taliban. Ben Wallace told reporters Johnson "will, at the G7 obviously, try to raise the possibility of the US extending". The UK is hosting a virtual meeting of the G7 on Tuesday for “urgent discussions” on the situation in Afghanistan. Once the US pulls out, the UK will have to follow suit, Wallace added. "It is very important for people to understand that the US has over 6,000 people at Kabul airport and when they withdraw, it will take away that framework (...) and we will have to leave as well," he said. The Taliban, meanwhile, has said it won"t form a government "as long as single US soldier present" in country. The Taliban will not announce the constitution of a government in Afghanistan as long as American soldiers remain on its soil, two sources within the Islamist movement told AFP on Monday. "It was decided that the formation of the government (...) would not be announced as long as a single American soldier was present in Afghanistan," said one of the sources. The information was confirmed by a second. In another development, Iran has called on "all parties" in Afghanistan to end the violence and to negotiate to form a government "representative of the diversity" of the country, and which wants good relations with its neighbors. "There is no military solution to the crisis", foreign affairs spokesman Saïd Khatibzadeh told a televised press briefing. "All groups and all political camps must refrain from resorting to force and work towards negotiation and dialogue," he said, adding that Tehran keeps open a permanent channel of communication with all sides in Afghanistan. Iran shares a border of more than 900 km with Afghanistan and had conflicting relations with the Taliban during their previous rule, which Tehran never recognized. But its Shi"ite government as recently showed signs of a rapprochement with the Taliban"s Sunni militia in the name of pragmatism. According to the United Nations High Commissioner for Refugees (UNHCR), Iran has accepted more than 3.46 million Afghans on its soil, the vast majority of them refugees or undocumented, more than 4% of the country"s population. Also Russia said it will not interfere in the stand-off between the Taliban and their opponents in Afghanistan. Kremlin spokesman Dmitry Peskov said on Monday that leaders of the Collective Security Treaty Organization member states discussed the standoff and its implications of “another civil war in Afghanistan." He said that, “Of course, no one is going to intervene in these events.” Taliban spokesman said Monday the group’s forces have surrounded Panjshir, the only one of Afghanistan’s 34 provinces that has not yet fallen to the Taliban. Several Taliban opponents have gathered in Panjshir. They include Amrullah Saleh, the vice president in the toppled government who claims to be the acting president, and Ahmad Massoud, son of the slain commander of the Northern Alliance militias that partnered with the US to drive the Taliban from power in 2001. The Collective Security Treaty Organization includes Russia, Belarus, Kazakhstan, Armenia, Kyrgyzstan and Tajikistan. In Islamabad, Pakistan’s interior minister said the Taliban have assured his country they will not allow the outlawed Pakistani Taliban — a separate militant group from the one in Afghanistan — to use Afghan soil for attacks against Pakistan. Sheikh Rashid Ahmed said on Monday that his ministry has information that amid the Taliban sweep across Afghanistan, some of the leaders and members of the Pakistani Taliban, or Tehreek-e-Taliban Pakistan, were freed from Afghan prisons. Ahmed said Islamabad was in contact with the Taliban over the matter. The Pakistani Taliban have claimed responsibility for several past attacks, including the 2014 deadly attack on a Peshawar school that killed 154 people, mostly schoolchildren. Islamabad alleges the Pakistani Taliban have been hiding in Afghanistan for the past several years, after fleeing military operations launched against them inside Pakistan. Ahmed also said that since last week, Pakistan has helped more than 2,000 foreigners and Pakistanis leave Afghanistan by air and land routes. Pakistan is issuing visas upon arrival to all diplomats, foreigners and journalists seeking to leave Kabul over security concerns. And, the chief of UNICEF has said there are around 10 million children in Afghanistan who “need humanitarian assistance to survive”. UNICEF Executive Director Henrietta Fore said in a statement there were an estimated one million children “projected to suffer from severe acute malnutrition over the course of this year and could die without treatment”. She added there are an estimated 4.2 million children out of school, and the UN has documented, since January, “over 2,000 grave violations of children’s rights”. “We anticipate that the humanitarian needs of children and women will increase over the coming months amidst a severe drought and consequent water scarcity, the devastating socioeconomic consequences of the COVID-19 pandemic and the onset of winter,” she said. Fore added that UNICEF would continue to have an on the ground presence in the country “now and in the days to come”. “We urge the Taliban and other parties to ensure that UNICEF and our humanitarian partners have safe, timely and unfettered access to reach children in need wherever they are,” she said. — Euronews with input from agencies.