US President Joe Biden welcomed Sweden's prime minister to the White House on Wednesday in a show of solidarity as the United States ramps up pressure for the Nordic nation's entry into NATO ahead of the alliance's summit next week. Biden said it was very important for Sweden to join, something that's been held up by objections from Turkey and Hungary. NATO requires the unanimous approval of all members to expand. Finland, which shares a more than 1,300-kilometers, border with Russia, joined NATO in April. But Sweden, which has avoided military alliances for more than 200 years, has been delayed.